以废弃蚕丝纺织品为原料制备CoSe/碳杂化催化剂

1成果简介

开发具有富集活性位点的自支撑结构对于提升过渡金属硒化物电催化剂的水裂解性能至关重要。本文，浙江理工大学陈祥、余厚咏教授团队、安徽大学张开富等在《Langmuir》期刊发表名为“Alcohol-Mediated Abandoned Silk Textile Transformation to Self-Support Carbon Frameworks Anchoring with CoSe for Bifunctional Electrocatalytic Water Splitting”的论文，研究通过协同醇介导的溶剂热法与可控热解策略合成的钴硒化物/废丝源碳（CoSe/SC）杂化催化剂。

值得注意的是，乙醇的引入将丝绸从随机卷曲结构转化为高度结晶的β片层结构，这在碳化过程中有效地保留了分级结构。所得的自支撑SC基质展现出卓越的电导率，使CoSe纳米颗粒能够实现最佳分散和电子耦合。电化学评估显示，优化后的CoSe/SC-2催化剂分别在10 mA cm–2电流密度下驱动HER和OER时，获得254.4 mV和278.7 mV的过电位。重要的是，Se–C键的形成赋予了钴硒化物与废丝绸衍生碳之间强烈的耦合，从而提高了CoSe/SC-2在整体水分解过程中的稳定性（130小时）。这项工作为设计基于再生生物质的过渡金属硒化物催化剂以实现高效电催化水分解提供了宝贵的见解。

2图文导读

图1. (a) Synthetic schematic illustration of CoSe/SC-2. (b) FTIR, (c) DSC, and (d) DTG of SC and SC-EtOH.

图2. (a) XRD curve of CoSe/SC-2. (b,c) The SEM images of CoSe/SC-2. (d–f) The TEM images of CoSe/SC-2. (g) The element mapping of CoSe/SC-2.

图3. Characterization of electrocatalysts’ physicochemical structure. The high-resolution XPS spectra of (a) Co 2p, (b) Se 3d, (c) C 1s, (d) N 1s.

图4. (a) LSV curves of RuO2, CoSe/SC-2, and CoSe + C for OER in O2-saturated 1.0 M KOH electrolyte at 10 mV s–1. (b) Tafel slopes derived from (a). (c) Comparison of the overpotential of different electrodes in (a) at current densities of 10 and 100 mA cm–2. (d) EIS spectra of samples under 1.62 V (RHE). (e) E–t chronopotentiometry stability measurement for samples at a constant current of 10 mA. (f) In situ Raman spectra of CoSe/SC-2.

图5. (a,b) The SEM images of CoSe/SC-2 after testing. (c) XRD curve of CoSe/SC-2 after testing. (d) Survey spectrum of CoSe/SC-2 after testing. (e,f) High-resolution XPS spectral comparison of Co and Se before and after testing.

图6. Electrochemical performance characterization of CoSe/SC-2 for HER. (a) LSV curves of samples for HER in O2-saturated 1.0 M KOH electrolyte at 10 mV s–1. (b) Tafel slopes derived from (a). (c) Comparison of the overpotential of different electrodes in (a) at current densities of 10 and 100 mA cm–2. (d) EIS spectra of samples under −0.28 V (RHE). (e) Comparison of the overall water-electrolysis efficiencies for Pt/C||RuO2, CoSe/SC-2, and CoSe + C couples. The inset shows the digital photograph of the CoSe/SC-2 electrolytic system. (f) E–t chronopotentiometry stability measurement for the samples with a fixed current density of 10 mA cm–2.

3小结

综上所述，我们通过乙醇介导的水热法与惰性气体煅烧工艺的结合，成功合成了自支撑型CoSe/SC电催化剂，并利用废弃的蚕丝纺织品作为可持续的碳前驱体。值得注意的是，水热过程中加入乙醇不仅促进了丝绸从随机卷曲结构向β片层构象的转变，从而提高了丝绸的结晶度并抑制其在溶剂中的溶解，还促进了钴硒化物的生长。所得的自支撑结构确保了活性位点与电解质的充分接触，而原位形成的Se–C键保证了CoSe在蚕丝衍生碳基底上的牢固附着，并实现了快速电子传输。因此，优化后的CoSe/SC展现出卓越的双功能活性和稳定性，在10 mA cm–2电流密度下，HER和OER的过电位分别为254.4和278.7，同时在整体水分解过程中具有130小时的出色长期耐久性。研究为利用废弃生物质资源设计金属硒化物电催化剂提供了新的方向和宝贵指导。

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来源：材料分析与应用