Unveiling O2 adsorption on non-metallic active site for selective photocatalytic H2O2 production
Jindi Yang, Hanqing Yin, Aijun Du, Mike Tebyetekerwa, Chuanbiao Bie, Zhuyuan Wang, Zhimeng Sun, Zhongguo Zhang, Xiangkang Zeng, Xiwang Zhang
Abstract
Photocatalytic oxygen reduction reaction (ORR) offers a promising pathway for sustainable hydrogen peroxide (H 2 O 2 ) production but faces challenges in developing catalysts with good ORR selectivity . Herein, we report that tailoring O 2 adsorption on non-metallic active sites can optimize ORR selectivity . This concept is demonstrated on three carbon nitrides with different atomic configurations: polymeric carbon nitride (PCN), lithium-poly triazine imide (Li-PTI), and sodium-poly heptazine imide (Na-PHI). Na-PHI emerges as a strong candidate for H 2 O 2 production due to the end-on adsorption mode and suitable adsorption strength with O 2 . Synthesized Na-PHI, PCN, and Li-PTI are characterized, with Na-PHI showing superior light absorption , charge carrier separation, and remarkable selectivity (92 %) for two-electron ORR. Consequently, Na-PHI achieves a high H 2 O 2 generation rate of 3.48 mmol g −1 h −1 , surpassing Li-PTI and PCN by 9.2 and 33 times, respectively. This study underscores the importance of O 2 adsorption on non-metallic active sites for selective photocatalytic H 2 O 2 generation.