Perovskite oxides play a vital role as electrocatalysts in water oxidation due to their flexible and unique electronic structures. In this work, Er-based perovskites ErCo_1−xFe_xO_3−δ (x = 0.0, 0.1, 0.3, 0.5, 0.7, and 10) denoted as EC, ECF-0.9, ECF-0.7, ECF-0.5, ECF-0.3, and EF, respectively, are synthesized by the sol–gel method. Then, ECF-0.9 is supported on sulfonated reduced graphene oxide (S-rGO) by a hydrothermal method, with weight ratios of 1 : 1 and 3 : 1 of ECF/0.9 to S-rGO (shown as ECF-0.9/S-rGO(50%) and ECF-0.9/S-rGO(75%), respectively). The structural properties and the morphology of the synthesized materials are studied using a series of different techniques. The prepared perovskites are then used as electrode materials for electrochemical water oxidation. ECF-0.9 reveals better activity than pure EF, EC, and other perovskite oxides in terms of overpotential, Tafel slope, electrochemically active surface area (ECSA), and charge transfer resistance (R_ct) values. Interestingly, when the optimized perovskite oxide catalyst ECF-0.9 is decorated on S-rGO sheets, the water oxidation activity is significantly improved. ECF-0.9/S-rGO(75%) exhibits superior activity for water oxidation with an overpotential of 290 mV@10 mA cm⁻² and a Tafel slope of 41 mV dec⁻¹. Finally, overall water splitting with ECF-0.9/S-rGO(75%) as the anode electrode shows a low electrolysis voltage of 1.60 V, alongside excellent stability for 20 h.

中文翻译：

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用于高效电化学水氧化的磺化还原氧化石墨烯封装钙钛矿型 ErCoFe 氧化物纳米颗粒


钙钛矿氧化物由于其灵活和独特的电子结构，在水氧化中作为电催化剂起着至关重要的作用。在这项工作中，通过溶胶-凝胶法合成了铒基钙钛矿 ErCo _1-xFe_xO _3-δ （x = 0.0、0.1、0.3、0.5、0.7 和 10），分别表示为 EC、ECF-0.9、ECF-0.7、ECF-0.5、ECF-0.3 和 EF。然后，通过水热法在磺化还原氧化石墨烯 （S-rGO） 上负载 ECF-0.9，ECF/0.9 与 S-rGO 的重量比为 1：1 和 3：1（分别显示为 ECF-0.9/S-rGO（50%） 和 ECF-0.9/S-rGO（75%））。使用一系列不同的技术研究合成材料的结构特性和形态。然后将制备的钙钛矿用作电化学水氧化的电极材料。ECF-0.9 在过电位、塔菲尔斜率、电化学活性表面积 （ECSA） 和电荷转移电阻 （R_ct） 值方面显示出比纯 EF、EC 和其他钙钛矿氧化物更好的活性。有趣的是，当优化的钙钛矿氧化物催化剂 ECF-0.9 装饰在 S-rGO 片材上时，水的氧化活性显着提高。ECF-0.9/S-rGO （75%） 表现出优异的水氧化活性，过电位为 290 mV@10 mA ^cm-2 和 41 mV ^dec-1 的塔菲尔斜率。最后，以 ECF-0.9/S-rGO（75%） 作为阳极电极的整体分解水显示出 1.60 V 的低电解电压，以及 20 h 的出色稳定性。