Cobalt Phosphides Nanocrystals Encapsulated by P-Doped Carbon and Married with P-Doped Graphene for Overall Water Splitting
Cobalt Phosphides Nanocrystals Encapsulated by P-Doped Carbon and Married with P-Doped Graphene for Overall Water Splitting
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由磷掺杂碳封装并与磷掺杂石墨烯结合的磷化钴纳米晶体用于整体水分解
DOI：
10.1002/smll.201804546
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发表时间：
2019-03-08
期刊：
影响因子：
13.3
通讯作者：
Han, Min
中科院分区：
文献类型：
--
作者：
Yang, Jing;Guo, Donghua;Han, Min
过渡金属磷化物（TMP）纳米结构作为一类重要的功能材料，在催化、储能等领域具有广阔的应用前景。虽然已经取得了很大的进展，磷化钴纳米晶体或相关纳米杂化物的相控制合成仍然是一个挑战，并且它们在整体水分解（OWS）中的应用没有系统地研究。本文以钴盐、植酸和氧化石墨烯为原料，在Ar/H-2气氛下，通过预合成的超分子凝胶在适当温度下的可控热转化，得到了三种由磷掺杂碳（PC）包裹并与磷掺杂石墨烯（PG）纳米杂化物结合的磷化钴纳米晶，包括CoP@PC/PG、CoP-Co2 P @PC/PG和Co2P@PC/PG。其中，混合相CoP-Co2 P @PC/PG纳米杂化物在碱性介质中对析氢和析氧均表现出较高的电催化活性。值得注意的是，使用它们作为双功能催化剂，制备的CoP-Co2 P @PC/PG|| CoP-Co2 P @PC/PG电解槽仅需要1.567 V的槽电压来驱动OWS以达到10 mA cm（-2）的电流密度，上级于它们的纯相对应物和最近报道的基于双功能催化剂的装置。此外，这种CoP-Co2 P @PC/PG|| CoP-Co2 P @PC/PG器件对OWS具有出色的稳定性。这一工作为基于相位工程优化TMP纳米结构提供了参考，并促进其在OWS或其他可再生能源中的应用。
As one class of important functional materials, transition metal phosphides (TMPs) nanostructures show promising applications in catalysis and energy storage fields. Although great progress has been achieved, phase-controlled synthesis of cobalt phosphides nanocrystals or related nanohybrids remains a challenge, and their use in overall water splitting (OWS) is not systematically studied. Herein, three kinds of cobalt phosphides nanocrystals encapsulated by P-doped carbon (PC) and married with P-doped graphene (PG) nanohybrids, including CoP@PC/PG, CoP-Co2P@PC/PG, and Co2P@PC/PG, are obtained through controllable thermal conversion of presynthesized supramolecular gels that contain cobalt salt, phytic acid, and graphene oxides at proper temperature under Ar/H-2 atmosphere. Among them, the mixed-phase CoP-Co2P@PC/PG nanohybrids manifest high electrocatalytic activity toward both hydrogen and oxygen evolution in alkaline media. Remarkably, using them as bifunctional catalysts, the fabricated CoP-Co2P@PC/PG||CoP-Co2P@PC/PG electrolyzer only needs a cell voltage of 1.567 V for driving OWS to reach the current density at 10 mA cm(-2), superior to their pure-phase counterparts and recently reported bifunctional catalysts based devices. Also, such a CoP-Co2P@PC/PG||CoP-Co2P@PC/PG device exhibits outstanding stability for OWS. This work may shed some light on optimizing TMPs nanostructures based on phase engineering, and promote their applications in OWS or other renewable energy options.