Dual-Plasmonic Au and CoNiO2 co-sensitized ZnO Membrane: Photothermal Effect Promotes Charge Separation for Enhanced Visible-Light-Infrared-Driven CO2 Reduction

Abstract

Photocatalytic CO2 reduction to CO is promising but limited by narrow light absorption, inefficient charge separation, and high energy barriers. Herein, we construct Au-plasmon-enhanced ZnO/CoNiO2 S-scheme heterojunctions (ZAC-X) on Zn foil via a simple hydrothermal method and UV light reduction method. Under UV-Vis-IR irradiation, ZAC-3 achieved a CO production rate of 9737.93 μmol•m -2 •h -1 , 4.5 times that under UV-Vis light (2175.73 μmol•m -2 •h -1 ), with high selectivity. Photoelectrochemical tests revealed a near 200 times enhanced photocurrent, confirming improved charge separation. Infrared thermal imaging shows dual Au/CNO LSPR effects elevated surface temperature, boosting carrier concentration. Enhanced hydrophilicity further promoted the reaction. TPD, in-situ FTIR, and DFT calculations demonstrate that ZAC-3 lowers the energy barriers for CO2→*COOH and CO desorption by 57% and 84%, respectively, facilitating CO2 activation and CO release processes. The superior performance stems from the synergy of the S-scheme, dual LSPR, and ordered array. This work offers a strategy for designing macrostructured CO2-to-CO catalysts and provides insights into synergizing heterojunction, plasmonic, and morphological engineering.