• Das, Tilak
• Ogale, Satishchandra
• Kumar, Santosh
• Kabir, Mubul
• Bhosale, Reshma
• Sharma, Neha

Abstract

<p>In view of their ability to absorb visible light and their high surface catalytic activity, metal sulfides are rapidly emerging as promising candidates for CO₂ photoreduction, scoring over the traditional oxide-based systems. However, their low conversion efficiencies due to serious radiative recombination issues and poor stability restrict their real-life applicability. Enhancing their performance by coupling them with other semiconductor-based photocatalysts or precious noble metals as cocatalysts makes the process cost intensive. Herein, we report the single-phase ternary sulfide Cu₃SnS₄ (CTS) as a robust visible-light photocatalyst for selective photoreduction of CO₂ to CH₄. It showed a remarkable 80% selectivity for CH₄ evolution with the rate of 14 μmol/g/h, without addition of any cocatalyst or scavenger. The mechanistic pathway for catalytic activity is elucidated by first principle calculations and in situ ATR, which imply a formaldehyde pathway of hydrocarbon production. The Cu-Sn termination of the surface is shown to be the key factor for competent CO₂ absorption and activation as confirmed from our X-ray spectroscopy measurements and first principle calculations. This study provides a foundation and insights for the rational design of sulfide-based photocatalysts to produce renewable fuel.</p>

Topics

• impedance spectroscopy
• surface
• phase
• semiconductor
• activation
• X-ray spectroscopy