Abstract Pt is the most effective electrocatalyst for hydrogen evolution reaction (HER). But its practical applications are severely hindered by the high cost and low abundance. Herein, we proposed a facile strategy to significantly reduce the Pt loadings for HER application. By introducing a Pt counter electrode in electrochemical cycling, trace Pt species were dissolved and redeposited on the working electrode composed of Mo2C nanoparticles anchored on the inner wall of highly ordered TiO2 nanotube arrays (TiO2 NTAs). Highly-dispersed Pt species were embedded in the crystal defects of Mo2C nanostructures with high dispersion and ultra-low Pt loading of ~13 μg/cm2. The as-prepared Pt-Mo2C/TiO2 NTAs exhibit highly electrocatalytic activities towards HER with an overpotential of 67 mV at the current density of 10 mA cm−2. Excellent stability has also been demonstrated. The mass activity of Pt-Mo2C/TiO2 NTAs is about 8-folds greater than that of commercial Pt/C electrode.

中文翻译：

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由固定在 TiO2 纳米管阵列中的具有超低 Pt 负载量的 Mo2C 纳米晶体组成的二元电催化剂用于析氢反应

摘要 Pt 是最有效的析氢反应（HER）电催化剂。但其高成本和低丰度严重阻碍了其实际应用。在此，我们提出了一种简便的策略来显着减少 HER 应用的 Pt 负载。通过在电化学循环中引入 Pt 对电极，痕量 Pt 物质被溶解并重新沉积在由固定在高度有序的 TiO2 纳米管阵列 (TiO2 NTAs) 内壁上的 Mo2C 纳米颗粒组成的工作电极上。高度分散的 Pt 物种嵌入 Mo2C 纳米结构的晶体缺陷中，具有高分散性和约 13 μg/cm2 的超低 Pt 负载。所制备的 Pt-Mo2C/TiO2 NTAs 表现出对 HER 的高度电催化活性，在 10 mA cm-2 的电流密度下具有 67 mV 的过电位。出色的稳定性也得到了证明。Pt-Mo2C/TiO2 NTAs 的质量活性是商业 Pt/C 电极的 8 倍。