Improved Photocatalytic Activities of g-C₃N₄ Nanosheets by B Doping and Ru-Oxo Cluster Modification for CO₂ Conversion

Abstract

g-C3N4 is a promising photocatalyst for CO2 conversion owing to its outstanding reduction potential. However, its shallow valence band position and sluggish water oxidation reaction restrict the overall CO2 photoreduction process. Herein, g-C3N4 nanosheets are first doped with B through thermal treatment of mixed NaBH4 and subsequently modified with highly dispersed Ru-oxo clusters by using tailored chitosan oligomers. The optimal Ru-oxo modified B-doped g-C3N4 exhibits an exceptional photocatalytic CO2 conversion rate with 22-fold improvement compared with pristine CN. Based on the results of electron paramagnetic resonance, atmosphere-controlled surface photovoltage spectroscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy, etc., it is confirmed that the improved photoactivities are attributed to the downward shift of the valence band to obtain the strong driving force for water oxidation along with extension of the visible light response region by B doping and to the capture of photogenerated holes to enhance charge separation and then to accelerate the water oxidation process from the modified Ru-oxo clusters.

Enhanced CO2 Reduction with Cs2AgBiBr6-gC3N4 Heterojunction Photocatalysts Prepared by Green Synthesis

“…The findings from these results indicate that the highest yield of oxidation product is observed in the case of 1:1 heterojunction followed by 1:2 and 1:5, which corroborates the results of CO 2 RR from Figure a. The generated protons migrate through the interface of the heterojunction to the adsorbed CO 2 to produce CH 4 . Also, the control experiment confirmed that a negligible fraction of the hole is responsible for a trace amount of CO evolution.…”

“…The generated protons migrate through the interface of the heterojunction to the adsorbed CO 2 to produce CH 4 . 37 Also, the control experiment confirmed that a negligible fraction of the hole is responsible for a trace amount of CO evolution. As such, the spatial separation of charge carriers across the S-scheme interface suppresses the rapid charge recombination and enhances the composite's redox ability as well as the photocatalytic efficiency.…”

2D/2D nitrogen-doped graphitic carbon nitride/cobalt sulfide nanostructures for fast photodegradation of methylene blue dye and real industrial sewage effluents

“…[1][2][3][4][5][6][7] In particular, textile industries cause more severe damage to the environment because they use harmful chemicals such as organic pollutants, heavy metals, cationic dyes, anionic dyes, azo dyes, pesticides, and oils. [8][9][10][11][12][13][14][15] Among them, Methylene Blue (MB) is a common cationic dye that is toxic and carcinogenic and is especially used in food processing, pharmaceutics, printing, and textile industries. It has a molecular formula of C 16 H 18 ClN 3 S, is odorless and is a dark green-colored powder but when added to water it appears as a blue solution at room temperature.…”

“…This is because of their exceptional light trapping and consumption abilities, spatially distributed reductive and oxidative active sites, and high redox capacities. 13,19 Nowadays, two-dimensional (2D) materials have attracted much interest in fabricating novel photocatalysts and energy storage due to their excellent physicochemical, optical, electrical, and thermal properties. 23 2D materials are also attractive because of their physical characteristics such as high elasticity, mobility, improved quantum transport, and electromechanical modulation.…”

“…This is because of their exceptional light trapping and consumption abilities, spatially distributed reductive and oxidative active sites, and high redox capacities. 13,19…”