Stabilized bismuth nanoplasmonics for selective CO2 reduction to methanol at a heterointerface
Haijiao Lu, Nasir Uddin, Zhehao Sun, Zibin Chen, Zackaria Mahfoud, Yilan Wu, Ary Anggara Wibowo, Zhicheng Su, Xinmao Yin, Chi Sin Tang, Xiaozhou Liao, Simon P. Ringer, Xin Zhao, Hieu T. Nguyen, Andrew T. S. Wee, Michel Bosman, Zongyou Yin
Abstract
Photocatalytic CO2 transformation into value-added chemicals has enormous industrial importance, which however is challenging to be operated under multifaceted performances in activity, selectivity, stability and regenerability. We successfully achieved this goal by integrating plasmonic bismuth nanoparticles and non-plasmonic redox heterojunctions. This maximizes the product selectivity by directing the reaction paths with the electric field of localized surface plasmon resonances (LSPRs). We attach non-noble plasmonic Bi particles with a shell of BiOCl to self-assembled TiO2 nanosheets, creating a transformative hybrid plasmonic nanostructure for CO2-to-methanol conversion. It exhibits high photoactivity (235.26 µmol g-1 h-1) and outstanding selectivity (~90% sole carbon/methanol product, ~10% H2) free of backward reactions, thanks to the synergistic effects of the hybrid nanostructure: complementary light absorption, strong local fields, and an adaptive redox heterojunction. Macro-to-micro experiments and simulations reveal that the BiOCl shell is responsible for stabilizing Bi to generate robust LSPRs, to induce 7-9 times local field enhancement, enabling efficient and selective CO2-to-methanol conversion at the TiO2-BiOCl hetero-interfaces. This work demonstrates a durable and easily-regenerable photocatalyst with the capability to tune the CO2 reduction pathway by plasmon fields. Moreover, it provides a unique paradigm to harvest hydrogen carriers (liquid methanol and hydrogen gas) from greenhouse gas CO2.