(220) facet exposed layered Co3O4: A bifunctional catalyst for electrochemical urea oxidation, and rapid 4-nitrophenol reduction to 4-aminophenol

IF 6.3 2区工程技术 Q1 ENGINEERING, CHEMICAL

Journal of water process engineering Pub Date : 2025-02-13 DOI:10.1016/j.jwpe.2025.107217

Mintesinot Dessalegn Dabaro, Meseret Ethiopia Guye, Hern Kim

{"title":"(220) facet exposed layered Co3O4: A bifunctional catalyst for electrochemical urea oxidation, and rapid 4-nitrophenol reduction to 4-aminophenol","authors":"Mintesinot Dessalegn Dabaro, Meseret Ethiopia Guye, Hern Kim","doi":"10.1016/j.jwpe.2025.107217","DOIUrl":null,"url":null,"abstract":"<div><div>Releasing urea-enriched wastewater from urea industries and 4-nitrophenol (4-NP) threatens human health and aquatic environments. The electrochemical urea oxidation reaction (UOR) offers a dual benefit: reducing wastewater pollution and producing green hydrogen via wastewater splitting. Meanwhile, 4-NP reduction to 4-aminophenol (4-AP) provides an added advantage, as 4-AP is widely used in pharmaceutical and food industries. In this study, layered Co3O4 nanosheets with exposed (220) facets were synthesized via a one-pot hydrothermal post-air-annealing method using cobalt acetate and urea without additives. The air-annealing temperature was critical, with the sample annealed at 500 °C (H120-500) exhibiting optimized nanosheets with exposed (220) facets, enhancing diffusion and electron transfer during UOR. H120-500 demonstrated superior performance, achieving a high turnover frequency (TOF) of 0.1493 s−1, a current density of 250 mA cm−2, stability over 72 h, a Tafel slope of 22.4 mV·dec−1, and requiring only 1.37 V vs RHE to reach 10 mA cm−2, surpassing state-of-the-art cobalt-based UOR electrocatalysts. Additionally, H120-500 achieved 99.64 % efficiency in reducing 4-NP to 4-AP within 2 min, with a pseudo-first-order rate constant (k) of 2.63 × 10−2 s−1 and durability over seven cycles. This approach offers a sustainable pathway for environmental remediation and green hydrogen production.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"71 ","pages":"Article 107217"},"PeriodicalIF":6.3000,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of water process engineering","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2214714425002892","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}

引用次数: 0

Abstract

Releasing urea-enriched wastewater from urea industries and 4-nitrophenol (4-NP) threatens human health and aquatic environments. The electrochemical urea oxidation reaction (UOR) offers a dual benefit: reducing wastewater pollution and producing green hydrogen via wastewater splitting. Meanwhile, 4-NP reduction to 4-aminophenol (4-AP) provides an added advantage, as 4-AP is widely used in pharmaceutical and food industries. In this study, layered Co₃O₄ nanosheets with exposed (220) facets were synthesized via a one-pot hydrothermal post-air-annealing method using cobalt acetate and urea without additives. The air-annealing temperature was critical, with the sample annealed at 500 °C (H₁₂₀-500) exhibiting optimized nanosheets with exposed (220) facets, enhancing diffusion and electron transfer during UOR. H₁₂₀-500 demonstrated superior performance, achieving a high turnover frequency (TOF) of 0.1493 s⁻¹, a current density of 250 mA cm⁻², stability over 72 h, a Tafel slope of 22.4 mV·dec⁻¹, and requiring only 1.37 V vs RHE to reach 10 mA cm⁻², surpassing state-of-the-art cobalt-based UOR electrocatalysts. Additionally, H₁₂₀-500 achieved 99.64 % efficiency in reducing 4-NP to 4-AP within 2 min, with a pseudo-first-order rate constant (k) of 2.63 × 10⁻² s⁻¹ and durability over seven cycles. This approach offers a sustainable pathway for environmental remediation and green hydrogen production.

Abstract Image

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of water process engineering Biochemistry, Genetics and Molecular Biology-Biotechnology

CiteScore

10.70

自引率

8.60%

发文量

846

审稿时长

24 days

期刊介绍： The Journal of Water Process Engineering aims to publish refereed, high-quality research papers with significant novelty and impact in all areas of the engineering of water and wastewater processing . Papers on advanced and novel treatment processes and technologies are particularly welcome. The Journal considers papers in areas such as nanotechnology and biotechnology applications in water, novel oxidation and separation processes, membrane processes (except those for desalination) , catalytic processes for the removal of water contaminants, sustainable processes, water reuse and recycling, water use and wastewater minimization, integrated/hybrid technology, process modeling of water treatment and novel treatment processes. Submissions on the subject of adsorbents, including standard measurements of adsorption kinetics and equilibrium will only be considered if there is a genuine case for novelty and contribution, for example highly novel, sustainable adsorbents and their use: papers on activated carbon-type materials derived from natural matter, or surfactant-modified clays and related minerals, would not fulfil this criterion. The Journal particularly welcomes contributions involving environmentally, economically and socially sustainable technology for water treatment, including those which are energy-efficient, with minimal or no chemical consumption, and capable of water recycling and reuse that minimizes the direct disposal of wastewater to the aquatic environment. Papers that describe novel ideas for solving issues related to water quality and availability are also welcome, as are those that show the transfer of techniques from other disciplines. The Journal will consider papers dealing with processes for various water matrices including drinking water (except desalination), domestic, urban and industrial wastewaters, in addition to their residues. It is expected that the journal will be of particular relevance to chemical and process engineers working in the field. The Journal welcomes Full Text papers, Short Communications, State-of-the-Art Reviews and Letters to Editors and Case Studies