Identification of photochemical effects in Ni-based photothermal catalysts

Abstract

Photochemical catalytic processes can reduce the activation energy so that reactions can occur under milder conditions. However, it is still unknown whether photochemical effects are present in photothermal catalysis over conventional transition metal materials. Herein, the representative photothermal CO2 hydrogenation catalyst, Ni@p-SiO2, is employed as a model system to quantitatively probe the contribution of photochemical effect. Through a series of catalytic and photophysical characterizations, it is found that negligible photochemical effect in the ultraviolet-visible region can be observed for the traditional Ni-based catalyst. The results of photoelectrochemistry (PEC) test further confirm that no apparent photochemical effect is present for the Ni@p-SiO2 catalyst in the aqueous-phase environment. It has been further evidenced that the photochemical contributions can be significantly amplified by introducing plasmonic metals, such as Au, into the system. This work provides a guideline for the design and construction of efficient synergetic photothermal-photochemical catalytic systems.