posted on 2023-11-24, 00:21authored byRuonan Wang, Mingjia Zhang, Shule Zhang, Jianzhong Zheng, Yiqing Zeng, Yan Yang, Jie Ding, Xu Wu, Qin Zhong
Enhancing the CO2 mass transfer and proton
supply in
the photocatalytic reduction of CO2 with H2O
into CH3OH (PRC-M), while avoiding the hydrogen evolution
reaction (HER), remains a challenge. Herein, we propose an approach
to control the surface coverage of CO2 and H2O by modifying interfacial wettability, which is achieved by modulating
the core–shell structure to expose either hydrophobic melamine-resorcinol-formaldehyde
(MRF) or hydrophilic NiAl-layered double hydroxides (NAL). Characterizations
reveal that an insufficient proton supply leads to the production
of competing CO, while excessive coverage of H2O results
in undesired HER. The NAL-MRF integrates hydrophobic and hydrophilic
interfaces, contributing to the CO2 mass transfer and H2O adsorption, respectively. This combination forms a microreactor
that facilitates the triphase photocatalysis of CO2, H2O, and catalyst, allowing for high local concentrations of
both *CO and *H without competing binding sites. Importantly, the
formation of covalent bonds and a Z-type heterojunction between hydrophilic
NAL and hydrophobic MRF layers accelerates the charge separation.
Furthermore, the density functional theory results indicate that the
NAL linking promotes the continuous hydrogenation of *CO. As a result,
an enhanced CH3OH yield of 31.41 μmol g–1 h–1, with selectivity of 93.62%, is achieved without
hole scavengers or precious metals.