Details

Autor(en) / Beteiligte

• Wu, Xuelian
• Ng, Yun Hau
• Wang, Liang
• Du, Yi
• Dou, Shi Xue
• Amal, Rose
• Scott, Jason

Titel

Improving the photo-oxidative capability of BiOBr via crystal facet engineering

Ist Teil von

• Journal of materials chemistry. A, Materials for energy and sustainability, 2017, Vol.5 (17), p.8117-8124

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Bismuth oxybromide (BiOBr) has emerged as a potential visible-light-driven photocatalyst with relatively high photocatalytic activity although modifications are still necessary to further promote its photocatalytic performance. Here, a facile chemical precipitation process was used to synthesize tetragonal BiOBr with a predominance of either {001} or {010} exposed crystal facets. Scanning electron microscopy revealed that BiOBr particles dominated by the {010} facet possessed a large plate-like morphology while the {001}-dominated BiOBr comprised smaller, more irregular particles. Ultraviolet-visible diffuse reflectance spectra and Mott-Schottky analysis highlighted a difference in electronic band structure of the two materials; BiOBr-010 possessed a valence band potential and a band-gap of 2.71 and 2.95 eV versus normal hydrogen electrode (NHE), respectively, while BOBr-001 exhibited values of 2.63 and 3.15 eV versus NHE, respectively. BiOBr-010 displayed a better photo-oxidative capability than BOBr-001 for both water oxidation and formic acid degradation (aqueous phase). The higher photo-oxidative capability of BiOBr-010 was attributed to the suppression of photo-induced electron/hole recombination. Additionally, the improved charge transfer efficiency and reduced charge transfer resistance in BiOBr-010 was revealed to be beneficial for enhancing photoelectrochemical (PEC) performance. The findings account for the better photo-oxidative activity and higher current density of BiOBr-010 despite its smaller specific surface area and illustrate the use of crystal facet engineering to promote photocatalytic performance.