open access

https://hdl.handle.net/2115/80467

A photoanode with plasmonic nanoparticles of earth abundant bismuth for photoelectrochemical reactions

英語

2020-12-01

Royal Society of Chemistry

Nanoscale advances

12

5591-5599

A wide range of technologies has been developed for producing hydrogen economically and in greener ways. Photoelectrochemical water splitting using photoelectrodes submerged in a bath electrolyte forms a major route of hydrogen evolution. The efficacy of water splitting is improved by sensitizing metal oxide photoelectrodes with narrow bandgap semiconductors that efficiently absorb sunlight and generate and transport charge carriers. Here we show that the efficiencies of photocurrent generation and photoelectrochemical hydrogen evolution by the binary TiO2/Sb2S3 anode increase by an order of magnitude upon the incorporation of the earth-abundant plasmonic bismuth nanoparticles into it. The ternary electrode TiO2/Bi nanoparticle/Sb2S3 illuminated with sunlight provides us with a photocurrent density as high as 4.21 mA cm(-2) at 1.23 V, which is fourfold greater than that of the binary electrode and tenfold greater than that of pristine TiO2. By using bismuth nanoparticles, we estimate the incident photon to current conversion efficiency at 31% and solar power conversion efficiency at 3.85%. Here the overall impact of bismuth nanoparticles is attributed to increases in the open-circuit voltage (860 mV), which is by expediting the transfer of photogenerated electrons from Sb2S3 nanoparticles to the TiO2 electrode, and short-circuit current (9.54 mA cm(-2)), which is by the plasmonic nearfield effect. By combining the cost-effective plasmonic bismuth nanoparticles with the narrow bandgap Sb2S3 on the TiO2 electrode, we develop a stable, ternary photoanode and accomplish high-efficiency photocurrent generation and hydrogen evolution.

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2516-0230