Visible Light-Driven Highly Selective CO₂ Reduction to CH₄ Using Potassium-Doped g-C₃N₅

Abstract

Establishment of an efficient and robust artificial photocatalytic system to convert solar energy into chemical fuels through CO2 conversion is a cherished goal in the fields of clean energy and environmental protection. In this work, we have explored an emergent low-Z nitrogen-rich carbon nitride material g-C3N5 (analogue of g-C3N4) for CO2 conversion under visible light illumination. A significant enhancement of the CH4 production rate was detected for g-C3N5 in comparison to that of g-C3N4. Notably, g-C3N5 also showed a very impressive selectivity of 100% toward CH4 as compared to 21% for g-C3N4. The photocatalytic CO2 conversion was performed without using sacrificial reagents. We found that 1% K doping in g-C3N5 enhanced its performance even further without compromising the selectivity. Moreover, 1% K-doped g-C3N5 also exhibited better photostability than undoped g-C3N5. We have also employed density functional theory calculation-based analyses to understand and elucidate the possible reasons for the better photocatalytic performance of K-doped g-C3N5.

Nitrogen‐rich graphitic carbon nitride (g‐C3N5): Emerging low‐bandgap materials for photocatalysis

“…Layer double hydroxide loaded on exfoliated g-C 3 N 5 was also reported in the literature with enhanced catalytic results of NH 3 production yield at 2.523 mmol g −1 h −1 . [69] This research also confirmed the role of nitrogen vacancies in g-C 3 N 5 networks, working as an active site for the adsorption and activation of N 2 , which could facilitate the production yield.…”

Intrinsic Charge Polarization in Bi19S27Cl3 Nanorods Promotes Selective CC Coupling Reaction during Photoreduction of CO2 to Ethanol

“…Hence, the UPS study is properly corroborating with the Mott–Schottky measurements. [ 20 ] Apparently, the E cb value of Bi 19 S 27 Cl 3 is sufficient to reduce CO 2 into CH 3 OH and CH 3 CH 2 OH and barely capable of producing CO (Figure S9, Supporting Information).…”

Synthesis and application of type-II heterojunctions based on CdS and g-C3N5 for efficient photocatalytic degradation of antibiotics

“…The peak at 293.0 eV raised due to the presence of the p-p* conjugation of g-C 3 N 5 . 19,33 The N 1s spectrum had three peaks at 398.2, 400.7 and 403.8 eV, which corresponded to C-NQC-bonds, [N-(C) 3 ] and p-p* conjugation 25,30,32 (Fig. 4c).…”

“…4a) proved that sample 3SCN consists of C, N, Cd and S. The result was consistent with the EDX elemental mapping, which further confirmed the existence of g-C 3 N 5 and CdS in the 3SCN composites. There were three peaks in the C 1s spectrum at 284.6, 286.2, and 287.9 eV, which were allocated to adventitious C, N 2 -CQN-and C-CH 2 , respectively 25,32 (Fig. 4b).…”