Lead-free Dion-Jacobson layered double perovskite as a photocatalyst for toluene oxidation

Two-dimensional (2D) perovskites have recently garnered widespread attention for their favorable properties, such as stability. However, their application in photoelectric fields is typically limited by the low mobility of charge carriers. Herein, a range of 2D lead-free double perovskites are fabricated using substituted aliphatic diamine cations. This modification leads to distortions in the octahedral structure of 2D perovskites, enhancing the connectivity of atomic orbitals at band edges. Notably (NH3(CH2)3NH3)2AgBiBr8, with minimized layer spacing compared to reported 2D lead-free double perovskites, shows the highest carrier mobility, surpassing its 3D counterpart. (NH3(CH2)3NH3)2AgBiBr8 displays excellent activity and stability in photocatalytic selective oxidation, achieving a toluene conversion up to 100% with a benzoic acid selectivity of 99% under visible light irradiation. Lower hydrophilicity as well as higher toluene adsorption capacity with the diamine cation substitutions could be responsible for the boosted photocatalytic performances.