Zhongxue Yang, Teng Liu, Huying Wang, Zhicheng Zhang, Hongzong Yin, Shaobin Wang, Geoffrey I. N. Waterhouse, Xiuguo Wang, Chao Ma, Li Peiqiang
A novel catalyst was developed for efficient photoelectrocatalytic of CO 2 to CH 3 OH. Through design and operation, Cu nanoparticles (Cu NPs) were successfully filled into ZrO 2 nanotubes (ZrO 2 NTs) by the pulse deposition method, and a Schottky junction was formed at the interface between Cu NPs and ZrO 2 NTs. The Schottky junction made the free energy barrier of CO 2 adsorption on Cu and ZrO 2 decrease to 0.44 eV and 0.24 eV, respectively, resulting in more favorable CO 2 adsorption. Thus, ZrO 2 acted as CO 2 main adsorption active site. Meanwhile, the Schottky junction not only decreased the activation energy of CO 2 (g) to ∗CO 2 , but also made more electron cloud migrate to the ZrO 2 side, resulting in a positive charge on Cu and the transfer of the negatively charged intermediates from ZrO 2 to Cu. The reaction free energy barrier in the rate-determining step (from ∗HCOO to ∗HCOOH) on Cu (1.18 eV) was much lower than that on ZrO 2 (1.45 eV), which is favorable for the catalytic reaction occurring on Cu. Thus, Cu acts as the main catalytic active site for CO 2 reduction to produce CH 3 OH. Furthermore, the in-situ Fourier Transform Infrared Spectroscopy (FT-IR) and density functional theory calculation confirmed the presence of the intermediates (∗CO 2 , ∗HCOO, and ∗CH 3 O). This catalyst design concept provides an important reference for the development of CO 2 catalytic materials.