Wang Ketao, Liu Xiaobin, Yu Qingping, Wang Xuanyi, Zhu Jiawei, Li Yanyan, Chi Jingqi, Lin Haifeng, Wang Lei
State Key Laboratory Base of Eco-Chemical Engineering, International Science and Technology Cooperation Base of Eco-chemical Engineering and Green Manufacturing, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, P. R. China.
College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao, 266042, P. R. China.
Small. 2024 May;20(20):e2308613. doi: 10.1002/smll.202308613. Epub 2023 Dec 10.
Due to the shortage of pure water resources, seawater electrolysis is a promising strategy to produce green hydrogen energy. To avoid chlorine oxidation reactions (ClOR) and the production of more corrosive hypochlorite, enhancing OER electrocatalyst activity is the key to solving the above problem. Considering that transition metal phosphides (TMPs) are promising OER eletrocatalysts for seawater splitting, a method to regulate the electronic structure of FeP by introducing Mn heteroatoms and phosphorus vacancy on it (Mn-FeP) is developed. As an OER electrocatalyst in seawater solution, the synthesized Mn-FeP achieves extremely low overpotentials (η = 376, η = 395 mV). In addition, the Pt/C||Mn-FeP couple only requires the voltage of 1.81 V to drive the current density of 1000 mA cm for overall seawater splitting. The density functional theory (DFT) calculation shows that Mn-FeP (0.21 e) has more charge transfer number compared with FeP (0.17 e). In-situ Raman analysis shows that phosphorus vacancy and Mn doping can synergistically regulate the electronic structure of FeP to induce rapid phase reconstruction, further improving the OER performance of Mn-FeP. The new phase species of FeOOH is confirmed to can enhance the adsorption kinetics of OER intermediates.
由于淡水资源短缺，海水电解是生产绿色氢能的一种有前景的策略。为避免氯氧化反应（ClOR）以及产生腐蚀性更强的次氯酸盐，提高析氧反应（OER）电催化剂的活性是解决上述问题的关键。鉴于过渡金属磷化物（TMPs）是用于海水分解的有前景的OER电催化剂，开发了一种通过在FeP上引入Mn杂原子和磷空位来调节其电子结构的方法（Mn-FeP）。作为海水电解液中的OER电催化剂，合成的Mn-FeP实现了极低的过电位（η = 376，η = 395 mV）。此外，Pt/C||Mn-FeP电极对在全海水分解中仅需1.81 V的电压就能驱动1000 mA cm的电流密度。密度泛函理论（DFT）计算表明，Mn-FeP（0.21 e）比FeP（0.17 e）具有更多的电荷转移数。原位拉曼分析表明，磷空位和Mn掺杂可以协同调节FeP的电子结构以诱导快速的相重构，进一步提高Mn-FeP的OER性能。已证实FeOOH的新相物种能够增强OER中间体的吸附动力学。
