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

Here, we report oxygen vacancy (V_O)-modified B/N-codoped ZnGa₂O₄ (V_O-B/N-ZGO) nanospheres, showing excellent photocatalytic H₂ production even without a Pt cocatalyst, which is better than that obtained with V_O-modified B-doped ZnGa₂O₄ (V_O-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 V_O-B/N-ZGO predominately originates from the improvement of charge separation and surface activation. Experimental characterization combined with the theoretical calculation method demonstrates that V_O-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, V_O-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.