High visible-light photocatalytic performance of stable lead-free Cs2AgBiBr6 double perovskite nanocrystals

Lead halide perovskite nanocrystals (NCs) have been recognized as a rather competitive candidates for potential advanced optoelectronic applications. But the toxicity of lead and the intrinsic instability are the key concerns for their large-scale commercialization. For addressing these tricky issues, we synthesized lead-free all-inorganic Cs 2 AgBiBr 6 double perovskite NCs adopting a facile hot injection approach. The as-prepared NCs could keep their structure stable either in air for more than two months or being heated at 300 °C in ambient atmosphere for 3 h. Moreover, Cs 2 AgBiBr 6 NCs were investigated for photocatalytic NO removal under visible-light irradiation, achieving an exciting removal rate of 97%, which is much higher than the previous reports as we know. In addition, the Cs 2 AgBiBr 6 NCs demonstrated outstanding recyclability for at least four cycles in NO removal. The photocatalytic mechanism of Cs 2 AgBiBr 6 NCs was further proposed. This investigation offers a new environmental photocatalyst to purify the air.