Surface Modification of Tin Dioxide via (Bi, S) Co‐Doping for Photoelectrocatalytic Reduction of CO₂ to Formate

Abstract

Photoelectrocatalytic reduction of CO 2 into useful fuels is a promising approach in terms of climate challenge and energy crisis. In this paper, a novel SnO 2 -based catalyst doped with bismuth (Bi) and sulfur (S) was synthesized via a simple hydrothermal method for photoelectrocatalytic reduction of CO 2 . The as-prepared catalyst demonstrates higher catalytic capability for CO 2 , in which the faradaic efficiency of formate reaches 55.6 % at an overpotential as low as~360 mV and the maximum current density is close to 9.33 mA.cm À 2 at À 1.4 vs Ag/AgCl with the doping ratio of 3 %, which is three times higher than pure SnO 2 . Meanwhile, the catalyst is more easily excited by visible light to reduce CO 2 due to the narrowing of band gap. The notable electrocatalytic performance for CO 2 reduction may be attributed to the defect caused by doping of Bi 3 + and S 2À into the lattice structure by replacing, respectively, Sn 4 + and O 2À . The catalyst may provide a novel strategy to promote the development of electrochemical reduction of CO 2 .

Elemental‐Doped Catalysts for Photoelectrochemical CO2 Conversion to Solar Fuels

“…For example, Li et al prepared Bi and S codoped SnO x catalysts through a hydrothermal method for PEC CO 2 reduction. [ 107 ]…”

“…Yupeng et al modified SnO 2 by Bi and S codoping to improve the photoresponse toward CO 2 reduction to formate. [107] The pristine SnO 2 has a polygon structure of ≈10 nm in size, with interplanar distances of 0.247 and 0.325 nm, corresponding to the ( 110) and ( 101) planes. Bi 3þ and S 2À doping to SnO 2 causes decreased interplanar distances to 0.241 and 0.325 nm for ( 110) and ( 101) planes, respectively.…”

Rational‐Designed Principles for Electrochemical and Photoelectrochemical Upgrading of CO2 to Value‐Added Chemicals

“…To boost the photoelectrocatalytic efficiency of pure semiconductors, heteroatoms‐doping into the structure of catalysts has been demonstrated to be an effective approach to facilitate the CO 2 /intermediate activation. Herein, Yang et al reported a Bi, S co‐doped SnO x catalyst for photoelectrocatalytic CO 2 reduction, [ 129 ] which provided abundant active sites and surface defects for formate production, and therefore achieved an ideal CO 2 conversion process with a relatively low overpotential and high partial current density compared with pure SnO 2 catalyst. The Bi, S co‐doped SnO x catalyst showed higher photocurrent density than that of SnO 2 , indicating that the heteroatoms doping could enhance the separation efficiency of photo‐excited electron‐hole pairs and improve the visible‐light absorption ability due to the narrower bandgap.…”

Recent progress of Bi-based electrocatalysts for electrocatalytic CO2 reduction

“…With respect to Bi and S co-doped SnO 2 electrocatalysts for the CO 2 RR, Li et al utilized a one-step hydrothermal method. 94 Different doping ratios were investigated (0%, 1%, 3%, 5% and 7%), and the FE formate results indicated that 3% doping was the best enabling a FE formate of 55.6% at −1.0 V vs. Ag/AgCl. Noticeably, this (Bi, S) co-doped SnO 2 was also capable of functioning as an effective photocatalyst, signifying that the development and design of catalysts with bifunctionalities ( i.e.…”