Unveiling the dynamic electronic structure of CuZn catalysts for solar-driven CO2 reduction
Journal
Applied Catalysis B: Environment and Energy
Journal Volume
395
Start Page
126897
ISSN
0926-3373
Date Issued
2026-10
Author(s)
Sundaresan, Ruspika
Tseng, Chung Sheng
Lai, Tai Ying
Chu, You-Chiuan
Wang, Guan-Bo
Tian, Feng-Ze
Hsu, Chia-Shuo
Tung, Ching-Wei
Abstract
Achieving high selectivity and efficiency in photoelectrochemical CO2 reduction remains a key challenge in solar-to-fuel conversion. Here, we report a CuZn alloy-modified black silicon (b-Si) photocathode fabricated via photo-assisted electrodeposition, achieving exceptional performance for selective CH4 generation. The hierarchical porous b-Si substrate enhances photon absorption and charge separation, while the Cu-Zn bimetallic catalyst tunes the surface electronic structure to favor methane production. The optimized Cu88Zn12@b-Si photocathode delivers a maximum CH4 Faradaic efficiency (FE) of 40%, outperforming both monometallic Cu and Zn catalysts. Compared to Cu@b-Si, the Cu88Zn12 case exhibits a 2.28-fold increase in CH4 efficiency at –0.99 V vs. RHE and a 0.2 V lower onset potential for CH4 formation. In situ X-ray absorption spectroscopy and in situ Raman analyses reveal stronger *CO binding and earlier *CHO intermediate formation, facilitated by hot electron excitation from localized surface plasmon resonance (LSPR) and enhanced electron transfer from Zn. The alloy interface effectively stabilizes Cu0, increases *CO coverage, and suppresses hydrogen evolution, enabling efficient and selective CO2 reduction. These results establish CuZn@b-Si as a high-performance, scalable platform for solar-driven methane production and offer mechanistic insights into plasmon-activated photoelectrochemical system.
Subjects
CO2 reduction
In situ Raman
In situ XAS
Photoelectrochemical reduction
Publisher
Elsevier BV
Type
journal article