Water splitting is a green strategy for hydrogen generation but greatly hindered by the sluggish anodic oxygen evolution reaction (OER). Herein, ultrathin rhodium-doped nickel iron layered double hydroxide nanosheets are successfully synthesized, which exhibit outstanding hydrogen evolution reaction (HER) and OER performance, and advanced overall water splitting. More impressively, the remarkable mass activity of 960 mA mg¹ at 1.55 V (1.7 times larger than NiFe-LDH) for urea electro-oxidation reaction (UOR) shows the great potential to surmount the sluggish OER for overall water splitting. A urine-mediated electrolysis cell is subsequently configured, delivering a current density of 10 mA cm^-2 with a potential of 1.35 V, which is 105 mV lower than that of urea-free counterpart. The enhanced catalytic activity and cell performance are attributed to the introduction of Rh into NiFe-LDH matrix by changing the electronic structure, allowing optimization of the adsorbed species, as confirmed by experimental measurements and computational analyses.

分解水是一种绿色的制氢策略，但由于缓慢的阳极氧气析出反应（OER）而大大受阻。本文成功合成了超薄铑掺杂镍铁层双氢氧化物纳米片，具有优异的析氢反应（HER）和OER性能，并具有良好的总水分解性能。更加令人印象深刻的是，尿素电氧化反应（UOR）在1.55 V（比NiFe-LDH大1.7倍）下具有960 mA mg ^-1的显着质量活性，显示了克服缓慢OER进行整体水分解的巨大潜力。随后配置一个尿液介导的电解池，提供10 mA cm ^-2的电流密度电位为1.35 V，比不含尿素的电位低105 mV）。如实验测量和计算分析所证实的，增强的催化活性和电池性能归因于通过改变电子结构将Rh引入NiFe-LDH基质中，从而使吸附物种最优化。