Double metals sites synergistically enhanced photocatalytic N₂ fixation performance over Bi₂₄O₃₁Br₁₀@Bi/Ti₃C₂T_x Ohm...

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, Bi₂₄O₃₁Br₁₀@Bi/Ti₃C₂T_x with double Ohm junction is successfully fabricated by in situ growth of metal Bi and loading Ti₃C₂T_x MXene on the surface of Bi₂₄O₃₁Br₁₀. The dual active sites of Bi and Ti₃C₂T_x MXene not only broaden the light adsorption of Bi₂₄O₃₁Br₁₀ 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 N₂ adsorption/activation and NH₃ desorption over Bi₂₄O₃₁Br₁₀@Bi/Ti₃C₂T_x. As a result, under mild conditions and without the presence of hole scavenger, the ammonia synthesis efficiency of Bi₂₄O₃₁Br₁₀@Bi/Ti₃C₂T_x-20 % reached 53.86 μmol g^-1_cat for three hours which is 3.2 and 53.8 times of Bi₂₄O₃₁Br₁₀ and Ti₃C₂T_x, respectively. This study offers a novel scheme for the construction of photocatalytic systems and demonstrates Ti₃C₂T_x MXene and metal Bi as a promising and cheap co-catalyst.