Enhanced CO2 photoreduction to CH4 via *COOH and *CHO intermediates stabilization by synergistic effect of implanted P and S vacancy in thin-film SnS2
Journal
Nano Energy
Journal Volume
128
ISSN
2211-2855
Date Issued
2024-09
Author(s)
Tadios Tesfaye Mamo
Mohammad Qorbani
Adane Gebresilassie Hailemariam
Raghunath Putikam
Che-Men Chu
Ting-Rong Ko
Amr Sabbah
Chih-Yang Huang
Septia Kholimatussadiah
Tadesse Billo
Mahmoud Kamal Hussien
Shuo-Yun Chang
Ming-Chang Lin
Wei-Yen Woon
Kuei-Hsien Chen
Abstract
Reduction of CO2 to value-added hydrocarbons through artificial photosynthesis is one of the way to address the energy crisis and climate change issues. It is known that lowering the activation energy of CO2 molecules on the photocatalyst surface and key intermediates is crucial in photocatalytic CO2 reduction. Herein, we present phosphorus-implanted 20-nm SnS2 continuous thin film with sulfur vacancies (i.e., SV-SnS2:P where P substitutes on S sites). The fabrication process involves thermal evaporation, post-sulfurization, and ion implantation. Our gas-phase photocatalytic experiments show an enhanced and selective CO2 photoreduction to CH4 with a yield of 0.13 µmol cm−2 and selectivity of 92 % under solar-light irradiation for 4 h over an optimal ∼4.5 % P and ∼16 % SV. Experimental observations, conducted through X-ray absorption near edge, in situ near ambient pressure X-ray photoelectron, and in situ Fourier transform infrared spectroscopies, along with first-principle density functional theory calculations. Results reveal that P dopant is significantly affected by nearby SV via local charge density transfer from P to the nearest Sn and next-nearest S neighbor atoms, consequently, leads to the stabilization of *COOH and *CHO intermediates, where asterisks stand for P as the active site. Our results demonstrate how active site modulation, without using precious co-catalysts, plays a crucial role in intermediate stabilization in a wireless photocatalysis process.
Publisher
Elsevier BV
Type
journal article