Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering , Nanjing Tech University , No. 5, Xin Mofan Road , 210009 Nanjing , P. R. China.
Building Energy Research Group, Department of Building and Real Estate , The Hong Kong Polytechnic University , Hung Hom, Kowloon , 999077 Hong Kong , P. R. China.
ACS Appl Mater Interfaces. 2018 Oct 10;10(40):34098-34107. doi: 10.1021/acsami.8b08239. Epub 2018 Sep 26.
The exploition of cost-efficient and high-performance catalysts to boost hydrogen generation in overall water splitting is crucial to economically obtain green hydrogen energy. Herein, we propose a novel electrocatalyst consisting of spherical RuS on S-doped reduced graphene oxide (s-RuS/S-rGO) with high catalytic behavior toward hydrogen evolution reaction (HER) in all pH conditions, especially in alkaline electrolytes. RuS/S-rGO delivers small overpotentials of 25 and 56 mV at current densities of 10 and 50 mA cm, respectively, and a low Tafel slope of 29 mV dec with good stability for 100 h in basic solutions. This performance is comparable to and even exceeds that of documented representative electrocatalysts, including the benchmark Pt/C; since the price of Ru is about 1/25th that of Pt, this novel electrocatalyst offers a low-cost alternative to Pt-based HER electrocatalysts. Ruthenium-centered sites of RuS in this hybrid catalyst are responsible for the HER active sites, and S doping in RuS also exerts an important function for the HER activity; density functional theory calculations disclose that the water dissociation ability and adsorption free energy of hydrogen intermediate adsorption (Δ G) for RuS are very close to those of Pt. A homemade electrolyzer with an s-RuS/S-rGO (cathode)//RuO/C (anode) couple presents a relatively low voltage of 1.54 V at a current density of 20 mA cm, while maintaining negligible deactivation over a 24 h operation.
开发经济高效且高性能的催化剂以促进整体水分解中的制氢对于经济地获取绿色氢能至关重要。在此，我们提出了一种由球形 RuS 负载在 S 掺杂还原氧化石墨烯（s-RuS/S-rGO）上的新型电催化剂，该电催化剂在所有 pH 条件下，特别是在碱性电解液中，对析氢反应（HER）具有高催化活性。RuS/S-rGO 在电流密度为 10 和 50 mA cm 时，分别表现出 25 和 56 mV 的小过电势，并且在碱性溶液中具有 29 mV dec 的低塔菲尔斜率和良好的稳定性，可稳定 100 h。该性能可与包括基准 Pt/C 在内的有记录的代表性电催化剂相媲美，甚至超过它们；由于 Ru 的价格约为 Pt 的 1/25，因此这种新型电催化剂为基于 Pt 的 HER 电催化剂提供了一种低成本替代品。该混合催化剂中 RuS 的 Ru 中心位点是 HER 的活性位点，而 RuS 中的 S 掺杂对 HER 活性也具有重要作用；密度泛函理论计算表明，RuS 的水离解能力和氢中间体吸附（ΔG）的吸附自由能非常接近 Pt 的。具有 s-RuS/S-rGO（阴极）//RuO/C（阳极）偶的自制电解槽在 20 mA cm 的电流密度下表现出相对较低的 1.54 V 电压，并且在 24 小时的运行过程中几乎没有失活。
