Dual-plasmonic Au and CoNiO2 co-sensitized ZnO membrane: photothermal effect promotes charge separation for enhanced visible-light-infrared-driven CO2 reduction

Abstract

Photothermal catalytic CO₂ reduction (PTCR) 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 achieves a CO production rate of 10 202.07 µmol m⁻² h⁻¹, 4.5 times that under UV-Vis light (2196.67 µmol m⁻² h⁻¹), with high selectivity. Photoelectrochemical tests reveal a near 200 times enhanced photocurrent, confirming improved charge separation. Infrared thermal imaging shows that dual Au/CNO LSPR effects elevate surface temperature, boosting carrier concentration. Enhanced hydrophilicity further promotes 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 activation and product release. 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.