Oxygen‐Deficient BiOBr as a Highly Stable Photocatalyst for Efficient CO₂ Reduction into Renewable Carbon‐Neutral Fuels

Abstract

A highly facile one‐pot ethylene glycol‐assisted solvothermal process was employed to fabricate bismuth oxybromide (BiOBr) with oxygen‐deficient defects. These defects played an indispensable role for superior photocatalytic CO2 reduction, in which the as‐prepared sample demonstrated a remarkable improvement of 3.3 and 5.7‐fold for CH4 production over pristine BiOBr and P25, respectively. The enhancement could be attributed to the presence of oxygen vacancies, which acted as the active sites for CO2 adsorption and activation. In addition, the oxygen–deficiency–induced defect states could effectively trap photogenerated electrons, thus improving the separation of the electron–hole pairs and significantly slow down the recombination rate of charge carriers. On top of that, oxygen‐deficient BiOBr exhibited long term stability (>50 hours of catalytic reaction) for CO2 photoreduction under simulated solar light, where no reducing agent or any post‐treatment was needed to regenerate the oxygen vacancies.

Interfacial defect engineering over fusiform bismuth vanadate photocatalyst enables to excellent solar-to-chemical energy coupling

“…Moreover, based on the high resolution Bi 4f spectrum of BiVO 4 -OV (Fig. S5 †) 19 For comparison with the BiVO 4 -P, the V 2p spectrum of the BiVO 4 -OV reveals that the binding energies of V 2p 3/2 and V 2p 1/2 peaks obviously shied to corresponding to peak position due to the formation of OVs attracting more electrons (Fig. S6 †).…”

Bismuth‐Based Photocatalysts for Solar Photocatalytic Carbon Dioxide Conversion

“…In addition, CO 2 molecules captured by oxygen vacancies were activated to CCO 2 À ,w hich was the ratelimiting step for CO 2 reduction. [144,145] This conclusionh as been supported by photocatalytic resultso ft he CO 2 reduction reaction. In our latestr eport, flexible BiOCl nanosheets with oxygen vacancies were synthesized through as imple solvothermal method, and changes to the photocatalytic process of BiOCl due to oxygen vacanciesw ere studied (Scheme 4).…”

“…[14][15][16][17][18][19] However,o nly af ew photocatalytic reduction reactions of pristine BiOX photocatalysts, such as photocatalytic CO 2 conversion, have been reported, to date. [142][143][144][145][146][147][148][149][150] [141] Ap hotocatalytic reactionu sually contains three important steps:1 )solar light harvesting, 2) charge separation and transportation,a nd 3) catalytic reduction and oxidation reactions.T hese steps largely depend on the intrinsic properties of the semiconductor photocatalyst.…”

Katalyse der Kohlenstoffdioxid‐Photoreduktion an Nanoschichten: Grundlagen und Herausforderungen

“…Dies wird bei der Deutung der Ergebnisse des Austauschs,d ie in Gegenwart von Graphen und Carbidnanoschichten gemessen wurden, hilfreich sein. Die Nanomaterialien lassen sich in zwei Gruppen einordnen:i )metallhaltige Photokatalysatoren wie Oxide, [11,39,48,53,54,70,[73][74][75][76][77][78][79][80][81] Chalkogenide, [49] Bismut-Oxyhalogenide, [82][83][84][85][86][87] Hydrotalcite [88] und Zeolithe; [89] ii)metallfreie Photokatalysatoren wie Graphen und seine Derivate (Graphenoxide (GO) und mit Heteroatomen dotiertes Graphen), [55,[90][91][92][93][94][95][96] g-C 3 N 4 [97][98][99][100][101][102] und kohlenstoffdotiertes h-BN. [55,56,72] Die Photoreduktionen von 13 CO 2 zu 13 CH 4 [55] und 13 CH 3 OH [54] wurden ebenfalls beschrieben.…”

“…[82] Es wurde gezeigt, dass Nanoschichten aus BiOCl, [83] BiOBr [84,87] und BiOI [51,86] photokatalytisch leistungsfähiger sind als die Bulkformen. BiOX besteht ausschließlich aus Hauptgruppenelementen.…”