A stable Ta3N5@PANI core-shell photocatalyst: Shell thickness effect, high-efficient photocatalytic performance and enhanced mechanism

Ta3N5 is a very promising visible-light-driven photocatalyst for water splitting and organic degradation. However, the low photocatalytic activity and poor photostability limit its application. To enhance the photocatalytic performance of Ta3N5, we prepared core-shell Ta3N5@polyaniline (PANI) by a chemisorption process. The effect of PANI content on the microstructure, optical, photoelectrochemical property and the photocatalytic activity of the samples were studied. The results showed that after the adsorption process, PANI was successfully coated on Ta3N5 with intimate contact and could significantly enhance the photocatalytic performance. The PANI shell thickness dramatically affected the photocatalytic activity. The Ta3N5@PANI 2 (PANI shell thickness: 0.9 nm) possessed the highest visible light photocatalytic H-2 production rate of 72.61 mu mol g(-1) h(-1) and RhB degradation rate of 0.041 min(-1), which were 3.2 and 16.6 times higher than those of Ta3N5. The Ta3N5@PANI exhibited excellent photostability and reusability. The superior photocatalytic performance of the Ta3N5@PANI was attributed to the synergic effect, including the intense interfacial interaction, enhanced visible light absorption, efficient charge separation and corrosive holes transfer from Ta3N5 to PANI. Furthermore, DFT calculations were applied to explore the interfacial interaction between PANI and Ta3N5. This study suggests that PANI modification can improve the photocatalytic application of Ta3N5 for H-2 production and RhB degradation. (C) 2019 Elsevier Inc. All rights reserved.