{"title":"Formation of flower-like Cu2O thin films induced by nitrate through electro-deposition for PEC water reduction","authors":"Yuliang Hao, Xiaolei Zuo, Weiyi Zhao, Jichuan Wu, Xiaoqiang lin, Hongyan Wang, Zeshan Wang, Chuanxiang Hao, Song Xue","doi":"10.1007/s11581-024-05805-w","DOIUrl":null,"url":null,"abstract":"<p>Cuprous oxide (Cu<sub>2</sub>O) is a highly promising photocatalyst that facilitates efficient water splitting and hydrogen production under light conditions. In this study, Cu<sub>2</sub>O thin film photocathodes were prepared through electro-deposition, with the inclusion of <span>\\(\\mathrm{NO}^{-}_{3}\\)</span> ions resulting in the formation of a flower-like microstructure. The size, distribution and roughness of these clusters were found to be greatly influenced by the concentration of the <span>\\(\\mathrm{NO}^{-}_{3}\\)</span> ions as confirmed by SEM and AFM characterizations. When 0.4 M <span>\\(\\mathrm{NO}^{-}_{3}\\)</span> ions were used, a flat and compact structure with the smallest ‘flower bud’ was obtained. This structure achieved a maximum photocurrent density of − 2.90 mA/cm<sup>2</sup> @0 V vs. RHE, which is 2.2 times greater than that of bare Cu<sub>2</sub>O. UV–Vis absorption, steady-state fluorescence spectroscopy and EIS measurements suggest that the compact microstructure facilitates enhanced ultraviolet absorption and separation of photogenerated holes and electrons. This results in a lower charge transfer resistance and a significant increase in photocurrent density. Additionally, a growth mechanism for the flower-like Cu<sub>2</sub>O was proposed. The XPS and EDS analyses indicate that the addition of <span>\\(\\mathrm{NO}^{-}_{3}\\)</span> during Cu<sub>2</sub>O formation results in the adsorption of <span>\\(\\mathrm{NO}^{-}_{3}\\)</span> onto the surface of the initial Cu<sub>2</sub>O grain. This, in turn, catalyses the electrocatalytic reduction of <span>\\(\\mathrm{NO}^{-}_{3}\\)</span> on the surface of Cu<sub>2</sub>O, leading to the formation of NH + 4 ions as evidenced by XPS.</p>","PeriodicalId":599,"journal":{"name":"Ionics","volume":null,"pages":null},"PeriodicalIF":2.4000,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ionics","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1007/s11581-024-05805-w","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Cuprous oxide (Cu2O) is a highly promising photocatalyst that facilitates efficient water splitting and hydrogen production under light conditions. In this study, Cu2O thin film photocathodes were prepared through electro-deposition, with the inclusion of \(\mathrm{NO}^{-}_{3}\) ions resulting in the formation of a flower-like microstructure. The size, distribution and roughness of these clusters were found to be greatly influenced by the concentration of the \(\mathrm{NO}^{-}_{3}\) ions as confirmed by SEM and AFM characterizations. When 0.4 M \(\mathrm{NO}^{-}_{3}\) ions were used, a flat and compact structure with the smallest ‘flower bud’ was obtained. This structure achieved a maximum photocurrent density of − 2.90 mA/cm2 @0 V vs. RHE, which is 2.2 times greater than that of bare Cu2O. UV–Vis absorption, steady-state fluorescence spectroscopy and EIS measurements suggest that the compact microstructure facilitates enhanced ultraviolet absorption and separation of photogenerated holes and electrons. This results in a lower charge transfer resistance and a significant increase in photocurrent density. Additionally, a growth mechanism for the flower-like Cu2O was proposed. The XPS and EDS analyses indicate that the addition of \(\mathrm{NO}^{-}_{3}\) during Cu2O formation results in the adsorption of \(\mathrm{NO}^{-}_{3}\) onto the surface of the initial Cu2O grain. This, in turn, catalyses the electrocatalytic reduction of \(\mathrm{NO}^{-}_{3}\) on the surface of Cu2O, leading to the formation of NH + 4 ions as evidenced by XPS.
期刊介绍:
Ionics is publishing original results in the fields of science and technology of ionic motion. This includes theoretical, experimental and practical work on electrolytes, electrode, ionic/electronic interfaces, ionic transport aspects of corrosion, galvanic cells, e.g. for thermodynamic and kinetic studies, batteries, fuel cells, sensors and electrochromics. Fast solid ionic conductors are presently providing new opportunities in view of several advantages, in addition to conventional liquid electrolytes.