Double metals sites synergistically enhanced photocatalytic N 2 fixation performance over Bi 24 O 31 Br 10 @Bi/Ti 3 C 2 T x Ohm junctions

At present, it is a research hotspot to realize green synthetic ammonia by using solar energy. Exploring cheap and efficient co-catalysts for enhancing the performance of photocatalysts is a challenge in the field of energy conversion. In order to boost the charge separation/transfer of the photocatalyst and widen the visible light absorption, Bi O Br @Bi/Ti C T with double Ohm junction is successfully fabricated by in situ growth of metal Bi and loading Ti C T MXene on the surface of Bi O Br . The dual active sites of Bi and Ti C T MXene not only broaden the light adsorption of Bi O Br but also serve as excellent 'electronic receptor' for synergically enhancing the separation/transfer efficiency of photogenerated electrons/holes. Meanwhile, temperature programmed desorption (TPD) result revealed that MXene and Bi can promote N adsorption/activation and NH desorption over Bi O Br @Bi/Ti C T . As a result, under mild conditions and without the presence of hole scavenger, the ammonia synthesis efficiency of Bi O Br @Bi/Ti C T -20 % reached 53.86 μmol g for three hours which is 3.2 and 53.8 times of Bi O Br and Ti C T , respectively. This study offers a novel scheme for the construction of photocatalytic systems and demonstrates Ti C T MXene and metal Bi as a promising and cheap co-catalyst.