Hydrogen production using zinc-doped carbon nitride catalyst irradiated with visible light

Abstract

Recently, graphitic carbon nitride (g-C 3 N 4 ) has been investigated as a photocatalyst for water splitting and organic dye degradation. In this study, we have developed a simple soft-chemical method of doping Zn into g-C 3 N 4 to prepare a metal-containing carbon nitride. The doping was confirmed by x-ray photoelectron spectroscopy, and diffusion reflectance spectra revealed a significant red shift in the absorption edge of Zn/g-C 3 N 4 . This hybrid material shows high photocatalytic activity and good stability for hydrogen evolution from an aqueous methanol solution under visible light irradiation (λ 420 nm). The hydrogen evolution rate was more than 10 times higher for a 10%-Zn/g-C 3 N 4 sample (59.5 µmol h −1 ) than for pure g-C 3 N 4 . The maximum quantum yield was 3.2% at 420 nm.

A facile modification of g-C3N4 with enhanced photocatalytic activity for degradation of methylene blue

“…Similar results were found in Yue's report when they doped zinc species into g-C 3 N 4 framework to prepare a metal-containing carbon nitride [27] and Wang's observation when they exfoliated the bulk g-C 3 N 4 to nanosheets [23].…”

“…Comparing with the pure g-C 3 N 4 , the (1 0 0) diffraction peak of g-C 3 N 4 -S x becomes gradually decrease with the increase of NaNO 3 amount and completely disappears when molar ratio of melamine to NaNO 3 is beyond 5:1. It might presumably be attributed to that the presence of NaNO 3 could partially destroy the graphitic structure to produce some fragments, and thus somewhat altered the in-plane structural repeating network [27]. The same phenomenon was also observed in g-C 3 N 4 -P x samples.…”

Metal halides supported on mesoporous carbon nitride as efficient heterogeneous catalysts for the cycloaddition of CO2

“…However, the UV absorption edge of 10ZnCl 2 /mp-C 3 N 4 was moved towards longer wavelengths in comparison with that of mp-C 3 N 4 . The phenomenon has also been previously reported over g-C 3 N 4 supported Fe [36], Zn [41], and V [42] catalysts. The shift of absorption peak after the loading of ZnCl 2 probably resulted from the d-p repulsion of the Zn 3d and N 2p orbits, namely a host-guest interaction between the ZnCl 2 and g-C 3 N 4 [36].…”

In situ surface alkalinized g-C3N4 toward enhancement of photocatalytic H2 evolution under visible-light irradiation

“…3 However, the low photocatalytic efficiency is still one of the most important factors restricting the practical application for the g-C 3 N 4 . Various strategies have been developed to improve the photocatalytic performance for g-C 3 N 4 , such as metal doping, [4][5][6][7] non-metal doping, [8][9][10][11][12] decoration with noble metal, [13][14][15] semiconductor [16][17][18][19] or graphene, [20][21][22] low-dimension nanostructure synthesis, 23,24 etc. 25,26 Among all the strategies to enhance the activity of photocatalyst, surface/interface modulation is one of the intensive research methods.…”