Halide perovskites have been emerging as promising photocatalytic materials for H 2 -evolution from water due to their outstanding photoelectric properties. However, the lack of proper surface reactive sites greatly hinders the photocatalytic potential of these fascinating compounds. Here, Mo 2 C nanoparticles have been anchored onto methylammonium lead iodide (MAPbI 3 ) as a non-noble-metal cocatalyst to promote H 2 -evolution reactions.
They published their work on May. 28 in Energy Material Advances .
“Photocatalytic water splitting has been considered as a promising route to store solar energy into hydrogen energy,” said paper author Xiaoxiang Xu, professor with the Shanghai Key Lab of Chemical Assessment and Sustainability, School of Chemical Science and Engineering, Tongji University. “Currently, halide perovskites have been gained great interest as photocatalysts for H 2 -evolution reactions, but they are normally deficient in surface reactive sites where photocarriers cannot be promptly transferred for surface redox reactions.”
Xu explained that the extremely acidic environment needed to stabilize halide perovskites in an aqueous solution restrains the choices of H 2 -evolution cocatalyst that can be deposited.
“The noble-metal cocatalyst Pt has been introduced to promote H 2 -evolution reactions but is still unsatisfactory probably due to the poor Pt/halide perovskite interfaces,” Xu said. “Robust non-noble-metal-based cocatalysts have gained serious attention as alternatives to noble-metal cocatalyst.”
However, their connections with halide perovskites are generally very weak often due to structural mismatch thereby preventing fast charge migrations from halide perovskites to these cocatalysts. According to Xu, Mo 2 C, a promising low-cost electrocatalyst for H 2 -evolution reaction, exhibits excellent electrocatalytic activity over a wide pH range thereby serving as a potential candidate cocatalyst for photocatalytic H 2 -evolution.
Mo 2 C is one of a few compounds that are stable in strong acids, Xu said, rendering it an excellent alternative cocatalyst for halide perovskites which are stabilized in strong acid during photocatalytic reactions, e.g. HBr and HI aqueous solution.
“The opposite Zeta potentials between Mo 2 C and MAPbI 3 ensure firm interconnections between these compounds,” Xu said. “In this paper, we illustrated recent research expediting H 2 -evolution over MAPbI 3 with a non-noble metal cocatalyst Mo 2 C under visible light.”
“We have successfully loaded Mo 2 C nanoparticles onto MAPbI 3 by an electrostatic-assembly method to fabricate Mo 2 C@MAPbI 3 composites,” Xu said.
“The Mo 2 C nanoparticles are found to be homogeneously and firmly anchored at the surface of MAPbI 3 ,” Xu said. “Thanks to the strong interconnections between Mo 2 C and MAPbI 3 , Mo 2 C@MAPbI 3 composites exhibit superior photocatalytic activity for H 2 -evolution from water which clearly surpasses pristine MAPbI 3 and Pt deposited MAPbI 3 under the same testing conditions.”
“Further analysis suggests that Mo 2 C nanoparticles not only facilitate charge separation in MAPbI 3 but also substantially expedite interfacial charge transfer for water reduction reactions,” Xu said. “These findings justify the Mo 2 C as an efficient non-noble-metal cocatalyst for halide perovskite photocatalysts that work under a highly acidic environment.”
The National Natural Science Foundation of China (Grant No. 51972233, 52172225), Natural Science Foundation of Shanghai (Grant No. 19ZR1459200), Science and Technology Commission of Shanghai Municipality (19DZ2271500) and the Fundamental Research Funds for the Central Universities supported this work.
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Reference
Authors: Jinxing Yu and Xiaoxiang Xu
Title of original paper: Expediting H 2 Evolution over MAPbI 3 with a Nonnoble Metal Cocatalyst Mo 2 C under Visible Light
Journal: Energy Material Advances
DOI: https://doi.org/10.34133/2022/9836095
Affiliations:
Shanghai Key Lab of Chemical Assessment and Sustainability, School of Chemical Science and Engineering, Tongji University, Shanghai 200092, China
About the Author:
Dr. Xiaoxiang Xu is a professor in School of Chemical Science and Engineering, Tongji University. He received his PhD degree from the University of St Andrews in 2010. From 2009 to 2013, he worked as a postdoc at the University of St Andrews. He joined the Tongji University in 2014. His research interest includes photocatalytic materials, environmental remediation, proton conductors and fuel cells, etc. He has co-authored more than 110 peer-reviewed papers.
Energy Material Advances
Experimental study
Not applicable
Expediting H2 Evolution over MAPbI3 with a Nonnoble Metal Cocatalyst Mo2C under Visible Light
28-May-2022
The authors declare that there is no conflict of interest regarding the publication of this article.