Study on g-C3N4/BiVO4 Binary Composite Photocatalytic Materials

Abstract

Recent studies have shown that the composite of semiconductor photocatalytic materials and g-C3N4 can effectively inhibit photocatalytic carrier recombination and enhance the adsorption performance of the composite photocatalytic materials, so that the composite photocatalyst has stronger photocatalytic activity. In this paper, three kinds of graphitic carbon nitride photocatalyst g-C3N4 with different morphologies were prepared using the same precursor system by the chemical cracking method. After characterization and application, the sample with the most significant photocatalytic activity was selected and the g-C3N4/BiVO4 heterostructure was synthesized by the simple solvent evaporation method, then the photocatalytic experiment was carried out. The results show that, when the content of BiVO4 in the composite sample is 1%, the photocatalytic activity of RhB was the highest, and the degradation rate could reach 90.4%. The kinetic results showed that the degradation of RhB was consistent with the quasi-primary degradation kinetic model. The results of the photocatalytic cycle experiment show that the photocatalytic performance remains unchanged and stable after four photocatalytic cycles. The existence of a g-C3N4/BiVO4 binary heterojunction was confirmed by UV/Visible diffuse reflection (UV-DRS) and photoluminescence (PL) experiments. Owing to the Z-type charge process between BiVO4 and g-C3N4, efficient carrier separation was achieved, thus enhancing the photocatalytic capacity. This work provides a new idea for the study of heterojunction photocatalytic materials based on g-C3N4.

Photocatalytic degradation of ammonia nitrogen using a Z-type nano-TiO2/LaMnO3 heterojunction

“…9a, the fluorescence spectra of nano TiO 2 , LMO and T/LMO at an excitation wavelength of 400 nm show an obvious emission peak in the scanning range of 500–700 nm, and the fluorescence intensity is inversely proportional to the photogenerated electron–hole recombination efficiency of the material. The more the photogenerated carrier recombination, 54 the more unfavorable the degradation of ammonia nitrogen. Due to the high rate of photogenerated electron carrier complexation, the fluorescence intensity of nano-TiO 2 was the strongest with the highest peaks, while the highest peak intensity of T/LMO was significantly lower than that of monomer materials, indicating that the synthesised composites greatly suppressed the rate of electron–hole pair complexation exhibiting an improved photocatalytic performance.…”

Fe-Doped g-C3N4/Bi2MoO6 Heterostructured Composition with Improved Visible Photocatalytic Activity for Rhodamine B Degradation

“…As the two different semiconductor particles are coupled, the Fe-g-C 3 N 4 /Bi 2 MoO 6 composite sample has an absorption edge at 487.8 nm, showing a slight red shift. The optical bandgap energy of the prepared semiconductor samples can be calculated using the following Tauc relation [ 22 , 23 ]: α(hv) = A (hv − E g ) 1/2 , where hv is the photon energy, A is a constant, and α and E g are the absorption coefficient and the optical bandgap energy (at wave vector k equal to zero) of the semiconductors. Tauc plots are based on the relationship between (αhv) 2 and hv to determine the optical bandgap energy for direct transitions.…”

“…As the two different semiconductor particles are coupled, the Fe-g-C 3 N 4 /Bi 2 MoO 6 composite sample has an absorption edge at 487.8 nm, showing a slight red shift. The optical bandgap energy of the prepared semiconductor samples can be calculated using the following Tauc relation [22,23]:…”

“…Bandgap engineering based on the heterojunction design of visible-light-driven photocatalysts is a promising and feasible route to increase the effective use of solar energy for high-speed chemical reactions and the treatment of organic pollutants in the environment [ 10 ]. The development of visible-light-derived photocatalysts based on coupling with graphitic carbon nitride (g-C 3 N 4 ) and oxide semiconductor nanoparticles has attracted considerable attention and interest [ 12 , 13 , 17 , 18 , 19 , 22 ].…”