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Oxygen Vacancy-Modified B-/N-Codoped ZnGa2O4 Nanospheres with Enhanced Photocatalytic Hydrogen Evolution Performance in the Absence of a Pt Cocatalyst C

Zhao, Peng, Li, Yanlu, Li, Lili, Bu, Shulin, Fan, Weiliu
Journal of physical chemistry 2018 v.122 no.20 pp. 10737-10748
boron, chemical bonding, hydrogen production, nanospheres, nitrogen, oxygen, photocatalysis, photocatalysts, semiconductors
Here, we report oxygen vacancy (VO)-modified B/N-codoped ZnGa₂O₄ (VO-B/N-ZGO) nanospheres, showing excellent photocatalytic H₂ production even without a Pt cocatalyst, which is better than that obtained with VO-modified B-doped ZnGa₂O₄ (VO-B-ZGO) or N-doped ZnGa₂O₄ (N-ZGO) and as high as about three times of that achieved with the undoped ZnGa₂O₄ (ZGO) photocatalyst. The dramatically enhanced photocatalytic activity of VO-B/N-ZGO predominately originates from the improvement of charge separation and surface activation. Experimental characterization combined with the theoretical calculation method demonstrates that VO-B/N-ZGO can show effective charge compensation more easily through the interaction of oxygen vacancies, interstitial boron, and substitutional nitrogen; especially for the formation of a B–N bond, it avoids the presence of semioccupied states as new recombination centers in a doped photocatalyst. In addition, VO-B/N-ZGO rich in reactive sites is generated by oxygen vacancy-modified B/N-codoping, which overcomes the limitation for most semiconductors without high H₂ evolution activities in the absence of a cocatalyst and provides a potentially new photocatalytic H₂ generation research.