JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2020
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IF 7.489
Hao Lei,Samarjeet Singh Siwal,Xiaoying Zhang,Qibo Zhang
Silver nanoparticles (NPs) developed on a copper substrate, Ag NPs/Cu, are synthesized by a novel and facile galvanic replacement method performed in Ethaline deep eutectic solvent (DES). It reveals that the Ag NPs could be well dispersed on the Cu support via an in-situ electrochemical oxidation-reduction (ECO-ECR) activation process, which deliver significantly enhanced activity and stability for the oxygen reduction reaction (ORR) in alkaline media. The in-situ redox tuning triggers a reversible phase transformation of the formed initially Ag NPs, Ag ↔ Ag 2 O, with surface reconstruction and gives rise to a strong metal-support interaction with tailored atomic/electronic structures, resulting in enhanced ORR activity. Impressively, the introduction of Ni II ions can regulate the galvanic replacement kinetics by mediating the diffusion of Ag I ions and subsequent growth of Ag on the Cu surface in Ethaline, leading to the formation of uniformly distributed Ag NPs. Coupled with redox activation, the optimal Ag-Ni 1 NPs/Cu_ECO-ECR exhibits ORR activity similar to that of the commercial state-of-the-art Pt/C catalyst, and better long-term durability (95% activity retention after 30,000 s), cyclic stability performance, and anti-poisoning capacity for methanol (96% after 3300 s), suggesting it a promising ORR electrocatalyst for practical application.
研究领域:
材料科学
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电化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Inorganics
·
2022
·Vol. 10
·期 7
·92
·
IF 3.149
Wang Zhang,Jiashuan Bao,Chenhui Xu,Pengfeng Zhu,Xiangliang Pan,Rui Li
Silver nanowire (AgNW) networks with high transparency and conductivity are crucial to developing transparent conductive films (TCFs) for flexible optoelectronic devices. However, AgNW-based TCFs still suffer from the high contact resistance of AgNW junctions with both the in-plane and out-of-plane charge transport barrier. Herein, we report a rapid and green electrochemical redox strategy to in-situ weld AgNW networks for the enhanced conductivity and mechanical durability of TCFs with constant transparency. The welded TCFs show a marked decrease of the sheet resistance (reduced to 45.5% of initial values on average) with high transmittance of 97.02% at 550 nm (deducting the background of substrates). The electrochemical welding treatment enables the removal of the residual polyvinylpyrrolidone layer and the in-situ formation of Ag solder in the oxidation and reduction processes, respectively. Furthermore, local conductivity studies confirm the improvement of both the in-plane and the out-of-plane charge transport by conductive atomic force microscopy. This proposed electrochemical redox method provides new insights on the welding of AgNW-based TCFs with high transparency and low resistance for the development of next-generation flexible optoelectronic devices. Furthermore, such conductive films based on the interconnected AgNW networks can be acted as an ideal supporter to construct heterogeneous structures with other functional materials for wide applications in photocatalysis and electrocatalysis.Keywords:silver nanowires;transparent conductive films;chemical welding;electrochemical redox;charge transport
研究领域:
材料科学
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纳米技术
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电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2022
·
IF 4.598
Bo Zhang,Jie Luo,Zhi Chen,Lintong Wu,Jianqin Li,Yuanyuan Tian,Shengli Liu
Nb-doped WO 3 films were prepared on FTO substrates by a facile sol–gel dip coating method. The influence of Nb doping on the microstructure and electrochromic characteristics of the films have been explored. The results indicate that the pure WO 3 film can achieve a synchronizing modulation of visible and near-infrared light bands by suppling voltage. However, the Nb-doped WO 3 films exhibit an ability of independent and selective transmittance modulation in both bands. Moreover, the Nb-doped WO 3 films undergo two electrochromic processes at different voltages, which are local surface plasmon resonance (LSPR) electrochromic process and electrochemical redox electrochromic process, respectively. These two electrochromic processes exhibit a unique photoelectric conversion behavior, that is, the reversible “bleached and warm” - “bleached and cool” - “colored and cool” modes. Additionally, with the increase of Nb doping content, the LSPR electrochromic effect becomes stronger. The high LSPR enhances the electrochemical redox electrochromic performance of the Nb-doped WO 3 films, enabling them to exhibit better electrochromic performance in the visible and near-infrared bands.
研究领域:
材料科学
·
电致变色材料
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纳米技术
✓ 已验证
DOI
高影响因子
Small
·
2022
·Vol. 19
·期 10
·2205619
·
IF 15.153
Fei Yu,Xiaochen Zhang,Peng Liu,Bingbing Chen,Jie Ma
Metal-organic frameworks (MOF) have attracted extensive attention due to their ultra-high specific surface area and tunable structure, the mechanism of direct utilization for capacitive deionization (CDI) defluorination remains undefined. Here, MIL-101(Cr) with ultra-high specific surface area, high water stability, and open metal sites (OMSs) is prepared by a hydrothermal method for defluorination of CDI. Carbon black is used as a “chain” to connect F-stored in the holes of MIL-101(Cr) (Cr-MOF)as “blocks” to enhance the conductivity and ion storage capacity of MIL-101(Cr)/carbon black electrodes (Cr-MOF electrodes). This simple construction method avoids the process complexity of in situ synthesis and performs better. These easily constructed “blockchain-like” Cr-MOF electrodes exhibit excellent defluorination capacity (39.84 mg NaF g electrodes −1 ), low energy consumption (1.2 kWh kg NaF −1 ), and good stability. The coupling of the electrochemical redox reaction of Cr 3+ /Cr 4+ with confined water is investigated using in situ and ex situ analysis methods combined with density functional theory (DFT), resulting in an unprecedented defluorination mechanism for Cr-MOF electrodes. This study opens up new ideas for the application of MOF in CDI, clarifies the removal mechanism of MOF, and lays a foundation for further promoting the application of raw materials with poor conductivity in the field of CDI.
研究领域:
环境科学
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材料科学
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化学工程
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
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