{"title":"Influence of nickel loading on reactivity of Ni/Fe bimetallic nanoparticles toward trichloroethene and carbon tetrachloride","authors":"Caijie WEI, Weizhong Wu, xufei zhao, Cheng Sun, Zehan Shi, jun Yang, Ming-Hong Wu","doi":"10.1039/d4en00426d","DOIUrl":null,"url":null,"abstract":"Bimetallic Ni/Fe-nanoparticles has been developed to enhance the dechlorination reactivity of nano-sized zero-valent iron. The physical structures of Ni/Fe-NPs with Ni loading ranged from 0.5wt% to 20wt% and the structure dependent reactivity variation towards to trichloroethene (TCE) and carbon tetrachloride (CT) have been fully investigated. A Ni-accumulated surface can be observed for the Ni/Fe-NPs with high Ni loading (20 wt.%), and the structure of other Ni/Fe NPs were identified as a Ni/Fe alloy-like structure with 5wt% Ni/Fe NPs owning the highest surface area and Fe0 content. While the best CT dechlorination rate was 2.5-fold of B-nZVI at 5wt% Ni loading, the best TCE reduction was 12-fold of B-nZVI at medium Ni loading (3wt%-5wt%). Since the primary TCE degradation mechanism is via atomic hydrogen (H*) whereas degradation of CT proceeds via direct electron transfer, the more efficient reduction mechanism for the Ni/Fe NP system was preferably H* reduction. The reduction-rate and the by-products yield variation between medium loading((3wt%-5wt%) and low/high (0.5wt%,20wt%) loading was more significant for TCE than CT. It has been found that Medium Ni loading (3wt%- 5wt%) obviously boosted the β-elimination of TCE to VC due to good storage of H* in Ni catalyst. The production of H* and enhanced electron migration rate were well demonstrated by CV curve and Tafel curve, respectively. The occurrence location of direct electron transfer and H* catalyst in bimetallic Ni/Fe system was further discussed.","PeriodicalId":73,"journal":{"name":"Environmental Science: Nano","volume":"24 1","pages":""},"PeriodicalIF":5.8000,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Science: Nano","FirstCategoryId":"6","ListUrlMain":"https://doi.org/10.1039/d4en00426d","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Bimetallic Ni/Fe-nanoparticles has been developed to enhance the dechlorination reactivity of nano-sized zero-valent iron. The physical structures of Ni/Fe-NPs with Ni loading ranged from 0.5wt% to 20wt% and the structure dependent reactivity variation towards to trichloroethene (TCE) and carbon tetrachloride (CT) have been fully investigated. A Ni-accumulated surface can be observed for the Ni/Fe-NPs with high Ni loading (20 wt.%), and the structure of other Ni/Fe NPs were identified as a Ni/Fe alloy-like structure with 5wt% Ni/Fe NPs owning the highest surface area and Fe0 content. While the best CT dechlorination rate was 2.5-fold of B-nZVI at 5wt% Ni loading, the best TCE reduction was 12-fold of B-nZVI at medium Ni loading (3wt%-5wt%). Since the primary TCE degradation mechanism is via atomic hydrogen (H*) whereas degradation of CT proceeds via direct electron transfer, the more efficient reduction mechanism for the Ni/Fe NP system was preferably H* reduction. The reduction-rate and the by-products yield variation between medium loading((3wt%-5wt%) and low/high (0.5wt%,20wt%) loading was more significant for TCE than CT. It has been found that Medium Ni loading (3wt%- 5wt%) obviously boosted the β-elimination of TCE to VC due to good storage of H* in Ni catalyst. The production of H* and enhanced electron migration rate were well demonstrated by CV curve and Tafel curve, respectively. The occurrence location of direct electron transfer and H* catalyst in bimetallic Ni/Fe system was further discussed.
期刊介绍:
Environmental Science: Nano serves as a comprehensive and high-impact peer-reviewed source of information on the design and demonstration of engineered nanomaterials for environment-based applications. It also covers the interactions between engineered, natural, and incidental nanomaterials with biological and environmental systems. This scope includes, but is not limited to, the following topic areas:
Novel nanomaterial-based applications for water, air, soil, food, and energy sustainability
Nanomaterial interactions with biological systems and nanotoxicology
Environmental fate, reactivity, and transformations of nanoscale materials
Nanoscale processes in the environment
Sustainable nanotechnology including rational nanomaterial design, life cycle assessment, risk/benefit analysis