Effect of graphitic carbon nitride microstructures on the activity and selectivity of photocatalytic CO2 reduction under visible light

Abstract

Two kinds of graphitic carbon nitride (g-C 3 N 4 ) were synthesized through a pyrolysis process of urea or melamine. It is found that the obtained g-C 3 N 4 , as photocatalysts, can reduce CO 2 to organic fuels under visible light, and exhibit different photoactivity and selectivity on the formation of CH 3 OH and C 2 H 5 OH. The product derived from the urea (denoted as u-g-C 3 N 4 ) shows a mesoporous flake-like structure with a larger surface area and higher photoactivity for the CO 2 reduction than the non-porous flaky product obtained from melamine (denoted as m-g-C 3 N 4 ). Moreover, using u-g-C 3 N 4 as a photocatalyst can result in the formation of a mixture containing CH 3 OH and C 2 H 5 OH, while m-g-C 3 N 4 only leads to the selective formation of C 2 H 5 OH. The present interesting findings could shed light on the design of efficient, eco-friendly and convenient photocatalysts and the tuning of their photoreactivity in the field of sustainable light-to-energy conversion.

Enhanced photocatalytic H2 evolution over CdS/Au/g-C3N4 composite photocatalyst under visible-light irradiation

“…The two diffraction peaks coinciding with g-C 3 N 4 are observed for the three samples. 26 Compared to g-C 3 N 4 , the XRD pattern of the Au/g-C 3 N 4 composite exhibits four extra peaks at 38. (220), and (311) planes of Au, respectively.…”

A perspective on perovskite oxide semiconductor catalysts for gas phase photoreduction of carbon dioxide

“…Based on these principles, various photocatalysts, including metal oxides (e.g., TiO 2 , [8] ZnO, [40] BiVO 4 , [41] and Ga 2 O 3 [ 42] ), metal sulfides (e.g., CdS [9] and ZnS [43] ), metal phosphides (e.g., GaP [10] ), nitrides (e.g., C 3 N 4 [ 44] ), etc., have been reported for CO 2 reduction. Among them, perovskite oxide semiconductor photocatalysts are good candidates for CO 2 reduction due to their unique physical and chemical properties, including their stability, their controllable structure and their ability to be doped in two different cation sites.…”

Photocatalysts with adsorption property for dye-contaminated water purification

“…6 The strong peaks at 31. aromatic N bonded to carbon atoms (C=N-C), the tertiary N bonded to carbon atoms in the form of N-(C)3 and N-H side groups, respectively, can be seen. [30][31] A weak peak at 404.5 eV ascribing to the π-excitations is also seen. 32 The high-resolution C 1s XPS spectrum of respectively.…”

“…32 The high-resolution C 1s XPS spectrum of respectively. [31][32] The graphitic carbon C-C at 284.8 eV can usually be observed in carbon nitrides. 16,33 The XPS survey scan of ZnO-LDH@C3N4 composite is shown in Figure 6 The XPS spectra for ZnO-LDH are illustrated in Figure 6-3.…”

“…[31][32] It's revealed that stacking products can be derived from different interlayer contents or different orientation of the same anionic species compensating for host layer charge in LDH materials. 33 Moreover, the stacking is not only influenced by the anionic species but also influenced by the M 2+ /M 3+ ratio, the metallic composition ratio in starting brucite influences the staging phenomena of LDH.…”