Modified g-C3N4 based visible light catalyst, and preparation method and application thereof

Abstract

The invention discloses a modified g-C3N4 based visible light catalyst, and a preparation method and an application thereof; a purpose comprises that a g-C3N4 base is modified by using a NaBH4 reduction method, and a band gap width and position are changed, so the response range to visible light is increased, and through changing of positions of a valence band and a conduction band, the catalyst can perform photocatalytic oxidation of water and reduces dissolved oxygen in the water to produce hydrogen peroxide; therefore, the technical problems in the prior art that modification of g-C3N4 canimprove the photocatalytic performance but has high cost, and low visible light utilization rate cannot be fundamentally changed are solved.

Description

technical field [0001] The invention relates to the field of photocatalytic materials, in particular to g-C 3 N 4 Modified g-C 3 N 4 Based photocatalysts and preparation methods. Background technique [0002] Since 1989, Liu and Cohen of the University of California theoretically proposed β-C 3 N 4 Since covalent crystals, nitrogen carbides have therefore received extensive attention from scientists in the field of photocatalysis. In 1989, A.Y.Liu and M.L.Cohen based on the β-Si 3 N 4 The crystal structure of β-C is theoretically predicted by the first-order pseudopotential band method under the local density of state approximation by replacing Si with C 3 N 4 (That is, carbon nitride) This hardness is comparable to that of diamond and is a new covalent compound that has not been found in nature. In 1996, Teter and Hemley calculated that C 3 N 4 There may be five structures, namely α phase, β phase, cubic phase, quasi-cubic phase and graphite-like phase, among whi...

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Problems solved by technology

[0005] Aiming at the above defects or improvement needs of the prior art, the present invention provides a modified g-C 3 N 4 Based visible light photocatalyst, its preparation method and application, its purpose is to adopt NaBH 4 Reduction method for g-C 3 N 4 Modification of the base to change its band gap width and position, thereby increasing its response range to visible light, and by changing its valence band and conduction band position, so that it can photocatalytically oxidize water and reduce dissolved oxygen in water to produce hydrogen peroxide , thereby solving the prior art on g-C 3 N 4 Although modification can improve its photocatalytic performance, the cost is high, and the technical problem of low utilization rate of visible light cannot be fundamentally changed.

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