Highly dispersed PdS preferably anchored on In2S3 of MnS/In2S3 composite for effective and stable hydrogen production from H2S

As an important byproduct during natural gas exploitation, green utilization of hydrogen sulfide (H2S) by photocatalysis has offered us the possibility for production of clean hydrogen (H-2) from H2S with low energy consumption. In this work, we have successfully introduced well-dispersed palladium sulfide (PdS) which is preferably loaded on In2S3 of MnS/In2S3 composite for improved photocatalytic hydrogen evolution from H 2 S aqueous solution. In contrast to binary MnS/In2S3, ternary MnS/In2S3/PdS has exhibited a remarkable and stable hydrogen production rate of 22.7 mmol g(-1) h(-1) with an apparent quantum yield of 34% at around 395 nm. A comprehensive structure characterization of the ternary composite including scanning transmission electron microscopy (STEM) and X-ray absorption spectroscopy (XAS) in combination with theoretical calculations confirm the good dispersion of PdS in the composite. Moreover, we discovered that PdS preferably interact with In2S3 rather than MnS in the composite through Pd-S-In bond on the interface of the two. Photoluminescence (PL) spectra, surface photovoltage (SPV) spectra together with transient photocurrent and electrochemical impedance spectra (EIS) demonstrate the advantage of PdS for promoting the charge separation. This work sheds light on the positive effect on the enhanced activity of the corresponding system resulting from the preferable anchoring of highly dispersed PdS on In2S3 in the composite by chemical Pd-S-In bond. Not only the high dispersion but also the preferable anchoring of the co-catalyst in the composite could hence inspire people for more rational designs of ternary composite in future. (C) 2019 Elsevier Inc. All rights reserved.