Transition metal doping BiOBr nanosheets with oxygen vacancy and exposed {102} facets for visible light nitrogen fixation

Artificial photocatalytic N-2 reduction to NH3 under ambient conditions represents a promising alternative way for the industrial N-2 fixation by Haber - Bosch process. This work reports the simultaneous engineering of BiOBr nanosheets with exposed {102} facets by means of transition metal (Fe, Mo, Ni) doping and oxygen vacancies (OVs) that aid to expose internal metal dopants toward efficient visible light N-2 fixation. The synergy of transition metal doping and OVs results in the modulated band structures, improved charge carrier separation as well as electron transfer to N-2, thereby leading to enhanced N-2 adsorption and activation ability over modified BiOBr nanosheets. In particular, the Fe-doped BiOBr with OVs possesses the optimal photocatalytic activity of NH3 yield of 46.1 mu mol g(-1) h(-1) without any sacrificial agent, which is 6-fold that of pristine BiOBr. The findings will shed new light on rational engineering of adsorption, activation sites and charge carrier separation for designing efficient N-2 fixation photocatalysts.

Automated summary

Artificial photocatalytic N-2 reduction to NH3 under ambient conditions is a promising alternative to industrial N-2 fixation. This study demonstrated the engineering of BiOBr nanosheets with transition metal doping and oxygen vacancies to enhance visible light N-2 fixation efficiency. The synergy of transition metal doping and oxygen vacancies improved charge carrier separation and electron transfer, leading to enhanced N-2 adsorption and activation ability over modified BiOBr nanosheets.