274results about How to "Wide absorption range" patented technology

The present invention belongs to the field of radiation resisting technology, and is especially one kind of nanometer wave absorbing fiber. The nanometer wave absorbing fiber consists of nanometer wave absorbing particle of 1-100 nm diameter of fine fiber of 30-2000 nm diameter in the weight ratio of 3-35 to 65-97. The nanometer wave absorbing fiber has wide wave absorbing range, powerful wave absorbing capacity, lasting wave absorbing effect and high flexibility. It has wave absorbing function, as well as antistatic, bacteriostasis, biochemical protection and other functions.

The invention provides an organic dye which uses five-membered heterocyclic ring, derivatives thereof and a dye-sensitized solar cell prepared by the organic dye. The dye uses the five-membered heterocyclic ring or the derivatives thereof as a Pi unit, uses substituted triarylamine as an electron donor, uses cyanoacetic acid structure as an electron acceptor, and belongs to molecule of D-Pi-A structure. The dye molecule belongs to pure organic compounds, the structure of the materials is simple and is easy to be obtained; expensive materials of metal of Ru and purifying agent of polydextrose do not need to use, the compound yield is higher, so the total yield is between 40 percent and 70 percent; besides, the performance of spectral absorption and molar extinction coefficient and the like of the dye are excellent; and the peak value of the spectral absorption is over 550nm at the most, the molar extinction coefficient is over 48000M<-1>cm<-1>, the peak value and the coefficient are more than the Ru dye, therefore, the dye has wider absorption range to the sunlight. The dye-sensitized solar cell prepared by the organic dye has the maximum of quantum conversion efficiency of 97 percent and the highest photoelectric conversion efficiency of more than 8.0 percent.

The present invention is a near-infrared absorbing material having a repeating unit represented by general formula (1) or general formula (2) and a near-infrared absorbing agent containing it, and further comprising the near-infrared absorbing material or near-infrared absorbing agent Near-infrared absorbing composition and optical filter. (In the formula, M represents a metal atom, R 1 and R 4 Each independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, R 2 and R 3 Each independently represents a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group, or a substituted or unsubstituted alkylene group, and R 1 and R 2 , R 3 and R 4 can also combine with each other to form a ring, and Y 1 ~Y 4 Represents a direct bond or a heteroatom, wherein A represents a direct bond or a divalent organic residue. )

A nanocrystal with high light absorption efficiency and a broad absorption spectrum, and a photovoltaic device comprising the nanocrystal are disclosed. The nanocrystal of the present invention comprises a core, a first shell grown and formed on the surface of the core, and a second shell grown and formed on the surface of the core or the surface of the first shell. Besides, the core, the first shell, and the second shell are a low energy gap material, a middle energy gap material, and a high energy gap material, respectively. Therefore, the nanocrystal has a great absorption in the ultraviolet range, the visible light range, and the infrared range; and the solar spectrum can be converted effectively to improve the light conversion efficiency thereof.

The invention relates to a visible light responsive photocatalysis material Ag@Ag3VO4 and a preparation method thereof. The Ag@Ag3VO4 photocatalysis material is of a near-spherical composite structure of depositing silver nano granules on the surfaces of silver vanadate granules, wherein the silver vanadate granules have the diameter of 6.5-7.5 mu m, and the surface deposited nano granules have the particle size of 5-25 nm. The invention also provides a preparation method of Ag@Ag3VO4. According to the invention, silver is deposited and loaded on the surface of Ag3VO4, thus the photocatalysis performance of Ag3VO4 is farther improved; and the method has the advantages of simple method, mild reaction conditions, convenience for operation, low energy consumption and the like.

The invention belongs to the field of thin film solar cells and relates to a perovskite-based inverted thin film solar cell and a preparation method thereof. The inverted thin film solar cell is based on an inverted planar structure, uses a FAPbI3 perovskite system as a light absorption layer, and is prepared by a solution method under a low temperature condition. The inverted thin film solar cell uses the novel FAPbI3 perovskite system as the light absorption layer. Compared with a conventional MAPbI3 perovskite system, the FAPbI3 perovskite system has a wider absorption range, higher phase inversion temperature, and better stability, prevents a high-temperature sintering defect in a conventional inverted structure, and may greatly decrease cost in industrialized production. The preparation method of theinverted thin film solar cell is simple, low in cost, good in repeatability, achieves a low-cost reel-to-reel mode, and has potential application value in the future industrialized production.

The invention relates to a sulfur-doped g-C3N4 / TiO2 heterojunction photocatalyst, and a preparation method and an application thereof. The chemical components of the catalyst are sulfur-doped C3N4 andTiO2 nano-particles, the microstructure of the catalyst contains a rod-like and lamellate structure, and the TiO2 nano-particles are distributed on the surface of the rod-like and lamellae structure.S-C3N4 prepared by mixing and calcining melamine and trithiocyanuric acid is compounded with TiO2 prepared by a solvothermal technology of tetra-n-butyl titanate to prepare the sulfur-doped g-C3N4 / TiO2 compound. The preparation method has the advantages of simple process, low cost and environment protection, and the prepared photocatalyst composite material has a very good application prospect inwastewater treatment.

The invention discloses a bismuth tungstate composite photocatalyst modified by a nitrogen-doped carbon quantum dot and a preparation method and application thereof. The composite photocatalyst is characterized in that bismuth tungstate is taken as a carrier, and is modified with the nitrogen-doped carbon quantum dot. The preparation method comprises the following steps: mixing bismuth nitrate, sodium tungstate and water, and stirring the mixture to obtain a bismuth tungstate precursor solution; mixing the bismuth tungstate precursor solution with a nitrogen-doped carbon quantum dot solution, and stirring the mixture to obtain a mixed solution; performing a hydrothermal reaction to obtain the bismuth tungstate composite photocatalyst. The composite photocatalyst has the advantages of environmental friendliness, high photo-induced electron-hole separating efficiency, high light absorbing efficiency, high photocatalysis activity, high photocatalysis stability and high corrosion resistance; the preparation method has the advantages of simple preparation process, low raw material cost, and easiness in controlling operation conditions. The composite photocatalyst is used for catalyzing degradation of antibiotic wastewater, and has the advantages of simple application method, high degrading efficiency and high repeatability, and has a very good practical application prospect.

The invention discloses a Bi / Aurivillius type oxide composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: firstly weighing soluble bismuth salt and 6 coordinated metal compound according to a mole ratio of (2-2.2) to 1, then dissolving the soluble bismuth salt and the 6 coordinated metal compound in alcohols solvents to prepare corresponding alcohol solutions, then dropwise adding metal coordination compound into an alcohol solution of the bismuth salt, uniformly mixing and subsequently carrying out solvothermal reaction, centrifuging after the reaction is finished, washing and drying to prepare the Bi / Aurivillius type oxide composite material, wherein the metals in the coordinated metal compound is 6-coordinate. The composite material has the special layered structure of the Aurivillius material; the elemental bismuth reduced in situ is uniformly distributed in the layered material of Aurivillius; the electron-cavity separation is improved; the light absorption range of the material is expanded; the photo-catalytic efficiency of the material is improved.

The invention provides a preparation method for a photocatalyst used for treating volatile organic compounds. The preparation method is characterized in that titanium dioxide is used as a main active component, a transition metal is added as an auxiliary agent, and a normal temperature spraying process is employed to load titanium dioxide on a metal or ceramic honeycomb carrier. The preparation method comprises the following concrete steps: A) dissolving titanyl sulfate in deionized water, adjusting a pH value to 7 to 10 by using a 5 to 25% ammonia-water solution, subjecting an obtained white precipitate to centrifugation and washing, mixing and beating the precipitate and deionized water and adjusting the pH value to 7 to 10 by using H2O2 and HCl with stirring so as to obtain a titanium sol; B) adding a surfactant into the titanium sol, adding micro metal oxide powder with stirring, adding a binder and carrying out high-speed shearing and uniform stirring so as to prepare a stable coating solution; and C) uniformly spraying the coating solution on the carrier and drying and roasting the carrier so as to obtain a finished catalyst product. The catalyst prepared by using the method has the characteristics of high volatile organic compound removal efficiency, a long life, easy loading and unloading, a low price, etc.

The invention discloses a silver phosphate / nitrogen-doped carbon quantum dot / bismuth vanadate Z type photocatalyst, a preparation method and application thereof. The Z type photocatalyst adopts bismuth vanadate as the carrier, and the bismuth vanadate is modified with nitrogen-doped carbon quantum dots and silver phosphate. The preparation method includes: preparation of a nitrogen-doped carbon quantum dot modified bismuth vanadium material; and mixing of the nitrogen-doped carbon quantum dot modified bismuth vanadium material with silver nitrate and disodium hydrogen phosphate dodecahydrate in water so as to obtain the Z type photocatalyst. The Z type photocatalyst provided by the invention has the advantages of high light absorption efficiency, high photoinduced electron-cavity separation efficiency, high photocatalytic activity, strong redox ability and the like, can efficiently degrade antibiotic wastewater, also has the advantages of simple application method, high degradation efficiency and good reutilization, and has good practical application prospect. The preparation method provided by the invention has the advantages of simple preparation process, easily controllable operating conditions, simple and easily available raw materials, low preparation cost and the like, and is suitable for continuous and large-scale mass production.

The invention belongs to the technical field of solar cell and relates to an organic dye using a multi-heterocyclic derivant as a conjugate unit and a dye-sensitized solar cell made from the dye. The dye uses a plurality of heterocyclic derivants as a pi unit and belongs to a molecule with a D-pi-A structure. The dye has wide absorption spectrum and high photoelectric conversion efficiency and has application prospect in the solar cell through substituting for a noble metal dye. The dye molecule belongs to a pure organic compound; compared with the prior ruthenium dye, the organic dye does not need to use expensive metal ruthenium as a raw material and glucan as a purifying agent; additionally, the synthesis yield is high (the total yield is more than 40 percent); therefore, the organic dye has the advantages of low cost and simple production; in addition, the absorption spectrum of the dye exceeds 550 nm and the molar extinction coefficient exceeds 45000 M-1cm-1, which are far larger than the absorption spectrum and the molar extinction coefficient of the ruthenium dye; therefore, the organic has wider absorption range to solar ray. The dye-sensitized solar cell prepared from the dye has high quanta conversion efficiency (IPCE); the maximum of the quanta conversion efficiency exceeds 95 percent (nm); and the photoelectric conversion efficiency is more than 8.0 percent and exceeds that of other most pure organic dye-sensitized solar cells.

The present invention relates to a luminescent photovoltaic generator (1) and a waveguide for use in such a photovoltaic generator. The photovoltaic generator comprises a photovoltaic cell (4) and a waveguide comprising a transparent matrix (2) having particles of an inorganic luminescent material dispersed therein and / or an inorganic luminescent material disposed at least one side thereof (6). The waveguide is associated with the photovoltaic cell (4), such that, in use, at least some of the light emitted from the luminescent material passes into the photovoltaic cell (4) to generate a voltage in the cell. In preferred embodiments, the inorganic luminescent material is a line emitter and the emission is due to a forbidden electronic transition within the material. The inorganic luminescent material may be selected from an inorganic phosphor, an inorganic fluorescent material and quantum dots, quantum rods and quantum core / shell systems. The photovoltaic generator (1) is an alternative to or an improvement upon known photovoltaic generators, which generally suffer from a lack of power yield per area.

The invention relates to a black ultraviolet-transmitting quartz tube which is prepared by using high purity quartz sand as basic raw materials in parts by weight, and compounding 0.5-4.0 parts by weight of colorant, wherein the colorant comprises sodium oxide (Na2O), sodium sulphate (Na2SO4), cuprous oxide (Cu2O), cobalt sesquioxide (Co2O3), manganese dioxide (MnO2), nickel oxide (NiO) and the like. The black ultraviolet-transmitting quartz tube molded by drawing through adopting a tube wall integral coloring preparation process has good uniformity and toughness, strong compression resistance and wide light absorption range. The cutoff wavelength thereof can reach 2100 nanometers, and the transmission rate is about 63 percent.

The invention discloses a 1T-MoS2-modified ZnCoS solid solution hollow dodecahedral nanocomposite and a preparation method and application thereof. Firstly, a ZnCo-MOF is calcined at a high temperature to obtain a derivative of the ZnCo-MOF, then the derivative and molybdate are subjected to hydrothermal vulcanization reaction to obtain a MoS2 / ZnCoS nanocomposite, and the ZnCo-MOF is a bi-metal organic framework material and is obtained through reaction of cobalt acetate, zinc acetate and dimethylimidazole. The bi-metal organic framework material with a large specific surface area and a stablethree-dimensional space structure is used as a template, the ZnCo bi-metal oxide derivative is obtained through high-temperature calcination, and finally a mixture of the derivative and the molybdateis subjected to hydrothermal vulcanization to obtain the transition metal sulfide nanomaterial with high catalytic activity. The prepared hollow polyhedral MoS2 / ZnCoS nanocomposite has high performance of producing hydrogen by water decomposition under photocatalysis.

The invention discloses thermal-insulation mortar. The thermal-insulation mortar consists of the following components in percent by mass: 1%-5% of an absorbent, 25%-50% of cement, 10%-30% of filler, 35%-60% of lightweight aggregates, 0.2%-1% of a reinforced fiber and 1%-4% of organic auxiliaries. The thermal-insulation mortar disclosed by the invention has a wide wave-absorbing range, and has good absorbing effect on electromagnetic waves within a range of 26.5 GHz-40 GHz in addition to the range of 2 GHz-18 GHz.

The invention relates to an anti-counterfeiting material which comprises an upconversion luminescent nano-UCNPs material with a core-shell structure and an inorganic perovskite quantum dot IPQDs material. The UCNPs material can excite visible light by infrared light, and emission light covers a region from ultraviolet light to infrared light, while the IPQDs material has wide absorption range andcan be excited by ultraviolet-visible light, an emission spectrum has a narrow half-peak width, and the light-emitted color is pure. According to the anti-counterfeiting material, after the upconversion luminescent nanomaterial and the inorganic perovskite quantum dot material are mixed, the emission light of the inorganic perovskite quantum dots is only showed under infrared light excitation. Therefore, ultraviolet light is not required to be used as excitation light, and the interference of background fluorescence can be avoided when the anti-counterfeiting material is used for counterfeiting prevention on a paper base. The invention also provides a preparation method of the anti-counterfeiting material and an application for printing, spraying or printing counterfeiting prevention.

The invention provides a organic dye containing thiophene ethylene and a dye-sensitized solar cell produced from the organic dye. The organic dye containing thiophene ethylene takes thiophene or the derivatives thereof as conjugated units so as to replace triarylamine functioning as an electron donor and cyanoacetic acid functioning as an electronic acceptor, and the thiophene or the derivatives thereof are molecules which are in D-Pi-A structures. The organic dye containing thiophene ethylene belongs to pure organic compounds and does not need expensive raw materials including metal such as ruthenium and decontaminant such as dextran glucan and has synthetic yield of 50 percent in total; in addition, the organic dye containing thiophene ethylene has the maximum spectral absorption peak of over 560 nm, the molar extinction coefficient of over 35*10Mcm, wider sunlight absorption range and other excellent performance superior to the performance of ruthenium dyes and most organic dyes. The dye-sensitized solar cell produced from the organic dye containing thiophene ethylene has the maximum quantum conversion efficiency of 90 percent and the maximum monochromatic incident photon-to-electron conversion efficiency (IPCE) of over 8.0 percent.

The invention relates to a special fertilizer applicator for a fruit tree, and belongs to the technology of agricultural machinery manufacturing. The special fertilizer applicator for the fruit tree is reliable to use, and good in fertilization effect, can adjust the fertilization depth, the fertilization distance and the fertilization amount. The technical scheme is that a rotary handle (1) and a bracket (2), a support wheel carrier (4) and the bracket (2), a work rack (10) and the bracket (2), and an opener (9) and the work rack (10) are respectively connected in a sleeving manner, and are respectively clamped and fixed by bolts; a fertilizer containing box (12) and a fertilizer apparatus (11) are respectively fixed at the upper and lower surfaces of the bracket of the fertilizer containing box through bolts; the fertilizer apparatus (11) adopts a universal external fluted roller fertilizer apparatus; power is provided for the fertilizer apparatus by a driving wheel / depth limiting wheel (7) through a transmission device (6); and a support wheel (5) and the support wheel carrier (4), the driving wheel / the depth limiting wheel (7) and the work rack (10), and a covering device (8) and the opener (9) are respectively hinged through bolt shafts.

The invention discloses a high-weather-resistant UV (ultraviolet) coating for a decorative plate and a preparation method of the high-weather-resistant UV coating. The coating is characterized by comprising, in parts by mass, 30-60 parts of an oligomer, 5-10 parts of thermoplastic acrylic resin, 15-50 parts of acrylate monomers, 3-6 parts of a photoinitiator, 0-30 parts of pigment, 0-10 parts of filler and 3-20 parts of an auxiliary agent. The invention further comprises the preparation method. The coating has the advantages that the decorative effect is good, the hardness of the coating is higher than 2H, the wear resistance is good, a coating film does not change in the extreme environment with the temperature ranging from subzero 40 DEG C to 60 DEG C and passes a 2000-hour salt fog resistance test, Q-Sun detection shows that the weather resistance of the coating can maintain 4,000 h, the production efficiency is high, few VOCs (volatile organic compounds) are discharged, little pollution is caused, the cost is low and the like.

The invention discloses a MnS / TiO2 composite nanotube array film for photo-induced cathodic protection and preparation and an application thereof, and relates to a composite nanotube photo-anode. The method includes the following steps: 1) substrate pretreatment: selecting a titanium foil as a substrate, carrying out ultrasonic cleaning successively in acetone, absolute ethyl alcohol and deionized water; 2) preparation of a TiO2 nanotube array thin film: adopting a two-step anodic oxidation method, with a platinum sheet as a counter electrode, in a working fluid, carrying out oxidization and calcination treatment on a titanium sheet, and generating a regular-morphology TiO2 nanotube array thin film on the substrate surface; and 3) preparation of the MnS / TiO2 composite film: adopting a continuous ionic layer adsorption reaction method, modifying TiO2 with MnS, and then carrying out calcination treatment to obtain the MnS / TiO2 nanotube array composite photo-anode. The method can significantly reduce the corrosion potential of 304 stainless steel, and has the characteristics of simple, feasible, safe and reliable operations, and high photoelectric conversion efficiency and stable performance of the product.

The invention discloses a bismuth oxybromide / silver silicate composite photocatalytic material and application. The composite photocatalytic material is of a composite structure of n-type silver silicate supported on the surface of a p-type bismuth oxybromide substrate, and is prepared by a simple precipitation method. The novel photocatalytic material is relatively high in photocatalytic activityand photocatalytic efficiency. Experiments show that the degradation properties of the photocatalytic composite material to organic matters are significant. In the irradiation of visible light, the composite photocatalytic material can be applied to the degradation of the organic matters in organic waste water, such as the treatment of the organic waste water containing phenol, methyl orange, rhodamine B and other organic pollutants.

The invention discloses a surface oxygen vacancy-modified bismuth oxybromide photocatalyst and a preparation method thereof. The invention relates to the technical field of photocatalysis. According to the invention, a bismuth oxybromide material is prepared through a chemical precipitation method, and the bismuth oxybromide material comprises BiOBr or Bi24O31Br10. Then, bismuth oxybromide powderis dispersed in a methanol-water solution, and nitrogen aeration treatment and visible light illumination are carried out, so that to the surface oxygen vacancy-modified bismuth oxybromide photocatalyst is obtained. The preparation method of the oxygen vacancy-modified bismuth oxybromide photocatalyst is simple, is easy to operate, and is high in repeatability and low in cost, and the absorption rate of visible light can be remarkably improved.

The invention relates to a photocatalytic material of gold nanorod coated with palladium nanoparticles at both ends and a preparation method of the photocatalytic material. The photocatalytic materialis of a dumbbell shaped structure, comprising a gold nanorod and palladium nanoparticles coated on both ends of the gold nanorod, wherein the middle part of the gold nanorod is not coated with palladium nanoparticles. The dumbbell-shaped structure of the palladium nanoparticles and the gold nanorod formed by the invention is of high stability and wide light absorption range, the preparation method is simple and reaction conditions are mild, the photocatalytic material is environmentally friendly, and is expected to be widely applied to the many aspects of photocatalysis, solar cells, photoelectric conversion and the like, broad application prospects are realized.

The invention belongs to the technical field of material preparation and solar energy photocatalysis and especially provides a carbon nitride hollow sphere photocatalyst, a preparation method and an application thereof. In the invention, a thermal fluid is used as a reaction medium, so that by means of a solvent action of the fluid under a subcritical status, reaction activity of a precursor is increased, and growth of a product is directly controlled at a low temperature to prepare the hollow sphere granules. The method solves the dependency on a template agent in a template-calcination technology in the prior art, which has the problems that high temperature calcination and corrosive removal of the template may cause collapse of the hollow structure and the product is low in light absorption range. The method achieves self-polymerization of a triazine ring monomer into the carbon nitride hollow sphere photocatalyst under a mild condition. By regulating the reaction parameters, polymerization degree is effectively changed, thereby controlling the physical and chemical properties of the product.

The invention relates to a solar cell photo-anode using a semiconductor thin film as a sensitizing agent and a preparation method of the solar cell photo-anode. The solar cell photo-anode is composed of a photo-anode body formed by a nano metal oxide semiconductor material and semiconductor sensitizing agent thin films covered on the surface, an electrolyte capable of generating oxidation and reduction reaction and a counter electrode, the photo-anode and the counter electrode are isolated by using a heat sealable film, the electrolyte is filled between the photo-anode and the counter electrode, the electrolyte at an interface where the photo-anode contacts with the electrolyte generates oxidation reaction, and the electrolyte at an interface where the counter electrode contacts with the electrolyte generates reduction reaction. The solar cell photo-anode has the advantages that an n-type wide-band-gap semiconductor material is adopted for the photo-anode, and the photo-anode of a solar cell is formed by growing various n-type semiconductor sensitizing agent thin films on the surface of the wide-band-gap semiconductor material by using atomic layer deposition technology , so that light absorbing range of the photo-anode is greatly widened; a semiconductor thin film sensitizing layer enables a wide-band-gap semiconductor and the electrolyte to be isolated, so that compositing of photo-generated carriers at the interface is substantially reduced, and efficiency of the solar cell is remarkably improved.

The present invention relates to a green-orange-red three-color fluorescent graphene quantum dot preparation method, wherein cheap pyrene is selected as a precursor and is nitrified at a low temperature to obtain an intermediate 1,3,6-trinitro pyrene, and low temperature solvothermal dehydrogenation, growth and in situ surface functionalization are performed under the effect of different solvents and different concentrations of a catalyst acetic acid. According to the present invention, the synthesized quantum dots can be stably dispersed in various organic solvents, the light emitting color or wavelength can be adjusted within 510-620 nm, and the fluorescence efficiency is high; and the synthesized quantum dot material provides attractive application prospects in the high and new technology fields of environmental protection, bio-nanotechnology, new energy sources, nanometer devices and the like, and the synthesis method has characteristics of simpleness, environmental protection and low energy consumption, and is suitable for industrial production.

The invention discloses a high-efficiency ternary organic solar cell based on a non-fullerene receptor alloy, which comprises a substrate, an anode, an anode modification layer, an active layer, a cathode modification layer and a cathode, and is characterized in that the active layer is a polymer donor PM6 and non-fullerene receptor alloy blended film; and the non-fullerene receptor alloy is a Y6:BTP-M alloy formed by mixing two non-fullerene receptors Y6 and BTP-M according to a certain proportion. By using the higher energy level and weaker crystallinity of BTP-M relative to Y6, the Y6: BTP-M alloy optimizes the energy level and morphology of the active layer at the same time, so that the PM6: Y6: BTP-M ternary organic solar cell obtains higher voltage and current than a PM6: Y6 binarycell; and finally, the highest energy conversion efficiency (PCE = 17.03%) of the existing single-junction organic solar cell is realized. Besides, the performance of the ternary organic solar cell isnot sensitive to the thickness of the active layer, and the PCE is 14% or above when the thickness of the active layer is 120-300 nm.

The invention discloses a frequency selective surface. The frequency selective surface comprises 100 units and a base plate, wherein the units are arranged into ten lines and ten rows, the units on each line are aligned in the horizontal direction, the units on each row are aligned in the vertical direction, the units are square sheets with the side length being 5.8 mm and thickness being 0.1 mm, a square hole with the side length being 4.2 mm is formed right in the middle of each unit, the distance between every two units is 1.9 mm, and the units are made of a material with relative dielectric constant being 1 and specific conductance being 200 s / m and are attached to the base plate made of an insulating material. The frequency selective surface is small in size, capable of being conformal with a system conveniently and convenient to install. The frequency selective surface (FSS) structure is large in wave absorbing bandwidth and can absorb waves within an ultra-wide-band range 2-18 GHz, reflection coefficient is smaller than -15dB, and the frequency selective surface is especially suitable for ultra-wide-band antennae.

The invention discloses preparation of a Z-type BiVO4-Au / g-C3N4 photocatalytic material and application of the material to photocatalytic reduction of CO2. The photocatalytic material comprises the following synthesis steps: preparing g-C3N4 and BiVO4 correspondingly through a thermal polymerization urea method and a hydrothermal method, loading Au on the g-C3N4 by using an Au precursor solution through a photodeposition method, and mixing and calcining the BiVO4 and Au / g-C3N4 to obtain the Z-type BiVO4-Au / g-C3N4 photocatalytic material. The photocatalytic material is applied to a suspension system of CO2 and H2O, and CO2 can be reduced to obtain a product CH3OH by taking 300-W xenon lamp as a light source. The photocatalytic material has a high visible light absorbing property and high photo-induced electron-hole separation efficiency and has important significance in solving the problems of energy and environment by converting CO2 into hydrocarbon energy.