Yang Wei, Li Han, Li Pengzhang, Xie Linhua, Liu Yumin, Cao Zhenbao, Tian Chuanjin, Wang Chang-An, Xie Zhipeng
School of Mechanical and Electronic Engineering, Jingdezhen Ceramic University, Jingdezhen 333403, China.
Institute of New Energy Materials and Devices, School of Materials Science and Engineering, Jingdezhen Ceramic University, Jingdezhen 333403, China.
Molecules. 2023 Sep 20;28(18):6709. doi: 10.3390/molecules28186709.
Developing robust and cost-effective electrocatalysts to boost hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs) is crucially important to electrocatalytic water splitting. Herein, bifunctional electrocatalysts, by coupling Co nanoparticles and N-doped carbon nanotubes/graphitic nanosheets (Co@NCNTs/NG), were successfully synthesized via facile high-temperature pyrolysis and evaluated for water splitting. The morphology and particle size of products were influenced by the precursor type of the cobalt source (cobalt oxide or cobalt nitrate). The pyrolysis product prepared using cobalt oxide as a cobalt source (Co@NCNTs/NG-1) exhibited the smaller particle size and higher specific surface area than that of the pyrolysis products prepared using cobalt nitrate as a cobalt source (Co@NCNTs/NG-2). Notably, Co@NCNTs/NG-1 displayed much lower potential -0.222 V vs. RHE for HER and 1.547 V vs. RHE for OER at the benchmark current density of 10 mA cm than that of Co@NCNTs/NG-2, which indicates the higher bifunctional catalytic activities of Co@NCNTs/NG-1. The water-splitting device using Co@NCNTs/NG-1 as both an anode and cathode demonstrated a potential of 1.92 V to attain 10 mA cm with outstanding stability for 100 h. This work provides a facile pyrolysis strategy to explore highly efficient and stable bifunctional electrocatalysts for water splitting.
开发坚固且具有成本效益的电催化剂以促进析氢反应（HERs）和析氧反应（OERs）对于电催化水分解至关重要。在此，通过简便的高温热解成功合成了双功能电催化剂，即通过将钴纳米颗粒与氮掺杂碳纳米管/石墨纳米片（Co@NCNTs/NG）耦合，并对其进行了水分解评估。产物的形态和粒径受钴源（氧化钴或硝酸钴）前驱体类型的影响。以氧化钴作为钴源制备的热解产物（Co@NCNTs/NG-1）比以硝酸钴作为钴源制备的热解产物（Co@NCNTs/NG-2）表现出更小的粒径和更高的比表面积。值得注意的是，在10 mA cm的基准电流密度下，Co@NCNTs/NG-1的析氢反应相对于可逆氢电极（RHE）的电位为-0.222 V，析氧反应相对于RHE的电位为1.547 V，低于Co@NCNTs/NG-2，这表明Co@NCNTs/NG-1具有更高的双功能催化活性。使用Co@NCNTs/NG-1作为阳极和阴极的水分解装置在达到10 mA cm时的电位为1.92 V，并且在100小时内具有出色的稳定性。这项工作提供了一种简便的热解策略，用于探索用于水分解的高效且稳定的双功能电催化剂。
