{"title":"Rational design of a g-C3N4/Bi2S3/ZnS ternary heterojunction photoanode for improved solar water splitting","authors":"Merin Joseph, Bhagatram Meena, Rosmy Joy, Sneha Joseph, Rajesh Kumar Sethi, Sebastian Nybin Remello, Suja Haridas, Challapalli Subrahmanyam","doi":"10.1039/d4se00147h","DOIUrl":null,"url":null,"abstract":"Photoelectrochemical (PEC) water splitting is an immensely effective method for producing hydrogen. In this study, we present the fabrication of an efficient photoanode based on a g-C<small><sub>3</sub></small>N<small><sub>4</sub></small>/Bi<small><sub>2</sub></small>S<small><sub>3</sub></small>/ZnS ternary heterojunction system using the doctor blade technique in combination with the successive ionic layer adsorption and reaction (SILAR) method. This ternary heterojunction demonstrated outstanding PEC performance, exhibiting a remarkable photocurrent density of 13.48 mA cm<small><sup>−2</sup></small> at 1.23 V <em>vs.</em> RHE in an alkaline medium. The enhanced photocurrent in the presence of hole scavengers could be due to sulfite oxidation. ZnS serves the dual purpose of acting as a passivation layer to prevent direct contact between Bi<small><sub>2</sub></small>S<small><sub>3</sub></small> and the electrolyte and offering an additional active energy state to enhance charge density, thus lending operational stability to the photoanode. The incident photon-to-current efficiency (IPCE) of the g-C<small><sub>3</sub></small>N<small><sub>4</sub></small>/Bi<small><sub>2</sub></small>S<small><sub>3</sub></small>/ZnS photoanode is 2.98%, which is substantially greater than 0.69% obtained with the g-C<small><sub>3</sub></small>N<small><sub>4</sub></small>/Bi<small><sub>2</sub></small>S<small><sub>3</sub></small> system. The g-C<small><sub>3</sub></small>N<small><sub>4</sub></small>/Bi<small><sub>2</sub></small>S<small><sub>3</sub></small>/ZnS photoanode exhibited a 94.6% average faradaic efficiency and high stability for up to 5000 seconds. Furthermore, electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) studies revealed efficient electron transfer at the heterojunction and thus were in accordance with the observed enhancement of the photocurrent density of the fabricated electrodes.","PeriodicalId":104,"journal":{"name":"Sustainable Energy & Fuels","volume":null,"pages":null},"PeriodicalIF":5.0000,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Sustainable Energy & Fuels","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1039/d4se00147h","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Photoelectrochemical (PEC) water splitting is an immensely effective method for producing hydrogen. In this study, we present the fabrication of an efficient photoanode based on a g-C3N4/Bi2S3/ZnS ternary heterojunction system using the doctor blade technique in combination with the successive ionic layer adsorption and reaction (SILAR) method. This ternary heterojunction demonstrated outstanding PEC performance, exhibiting a remarkable photocurrent density of 13.48 mA cm−2 at 1.23 V vs. RHE in an alkaline medium. The enhanced photocurrent in the presence of hole scavengers could be due to sulfite oxidation. ZnS serves the dual purpose of acting as a passivation layer to prevent direct contact between Bi2S3 and the electrolyte and offering an additional active energy state to enhance charge density, thus lending operational stability to the photoanode. The incident photon-to-current efficiency (IPCE) of the g-C3N4/Bi2S3/ZnS photoanode is 2.98%, which is substantially greater than 0.69% obtained with the g-C3N4/Bi2S3 system. The g-C3N4/Bi2S3/ZnS photoanode exhibited a 94.6% average faradaic efficiency and high stability for up to 5000 seconds. Furthermore, electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) studies revealed efficient electron transfer at the heterojunction and thus were in accordance with the observed enhancement of the photocurrent density of the fabricated electrodes.
期刊介绍:
Sustainable Energy & Fuels will publish research that contributes to the development of sustainable energy technologies with a particular emphasis on new and next-generation technologies.