Developing low-cost, high performance, stable non-noble bifunctional electrocatalysts for overall water splitting is of great importance for future energy supplement. Despite recent advances in the synthesis of transition metal selenide nanostructures, the fabrication of porous nanosheet based binder-free electrode with more active sites remains a major challenge. Herein, the self-templating construction of a porous CoSe₂ nanosheet array on carbon cloth (p-CoSe₂/CC) has been reported by vapor selenizing the preprepared α-Co(OH)₂ nanosheet array precursor. Arising from large active surface area, fast diffusion of generated gas and strong structural stability, the as-obtained p-CoSe₂/CC can serve as an efficient bifunctional electrocatalyst for both OER and HER in alkaline electrolyte, with a current density of 10 mA cm^–2 at overpotential of 243 mV for OER and 138 mV for HER, respectively. Moreover, when p-CoSe₂/CC is assembled as an alkaline electrolyzor, it only needs a cell voltage of 1.62 V at 10 mA cm^–2 and shows excellent long-term stability of 20 h. The versatile fabrication strategy with self-templated porous structure proves a new way to construct other advanced metal selenide for energy conversion and storage.

中文翻译：

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多孔CoSe ₂纳米片阵列的自模板构造作为整体水分解的高效双功能电催化剂

开发用于整体水分解的低成本，高性能，稳定的非贵金属双功能电催化剂对于未来的能源补充至关重要。尽管在过渡金属硒化物纳米结构的合成方面有最新进展，但是具有更多活性位点的多孔纳米片基无粘合剂电极的制造仍然是主要挑战。在本文中，已经报道了通过气相硒化预先制备的α-Co（OH）₂纳米片阵列前体在碳布上的自模板构造多孔CoSe ₂纳米片阵列（p -CoSe ₂ / CC）。由于存在较大的有效表面积，生成的气体快速扩散且结构稳定性强，因此获得了p -CoSe ₂/ CC可以用作碱性电解质中OER和HER的有效双功能电催化剂，在OER和HER分别为243 mV和138 mV的过电势下，电流密度为10 mA cm ^–2。此外，将p -CoSe ₂ / CC组装为碱性电解槽时，在10 mA cm ^-2时仅需要1.62 V的电池电压，并具有20 h的出色长期稳定性。具有自模板多孔结构的通用制造策略证明了构造其他用于能量转换和存储的高级金属硒化物的新方法。