This work spotlights the facile method to deposit cobalt oxide (CoO_x) nanoparticles as a cocatalyst on Fe-MOF-bpdc to enhance its photocatalytic activity for water oxidation reaction (WOR) under visible light irradiation to evolve gaseous O₂. Due to the soft conditions needed for the process developed, the framework structure of Fe-MOF-bpdc was maintained even after the deposition of CoO_x. The optimized CoO_x@Fe-MOF-bpdc composite showed enhanced activity towards visible-light-driven WOR as compared to pristine Fe-MOF-bpdc, the amount of evolved O₂ being increased by about 2 times at the maximum with CoO_x loading of 2 wt% as Co metal. Investigations on the wavelength dependence of visible-light-driven WOR on CoO_x@Fe-MOF-bpdc revealed that the direct photo-excitation of Fe-oxo clusters within Fe-MOF-bpdc plays an important role to initiate the reaction. Furthermore, it was found that the rate of 2-propanol oxidation reaction, which is a typical two-electron oxidation reaction, was hardly affected by CoO_x deposition, suggesting that CoO_x acts as a unique hole trapping site and more preferentially catalyse the four-electron oxidation reactions like WOR than the two-electron oxidation reaction.

中文翻译：

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纳米氧化钴沉积Fe-MOF-bpdc的设计，用于增强可见光促进的水氧化反应

这项工作射灯轻便方法为氧化钴沉积物（COO _X）纳米颗粒作为对Fe-MOF-BPDC的助催化剂，以加强在可见光照射下的水的氧化反应（WOR）其光催化活性演变气态Ò ₂。由于开发过程所需的软条件，即使在CoO _x沉积之后，Fe-MOF-bpdc的框架结构也得以保持。优化的CoO _X @的Fe-MOF-BPDC复合表现出增强的对可见光驱动WOR活性相比质朴的Fe-MOF-BPDC，的析出量Ò ₂在与CoO的最大而增加约2倍_X钴金属含量为2 wt％。对可见光驱动的WOR对CoO _x @ Fe-MOF-bpdc的波长依赖性的研究表明，Fe-MOF-bpdc中的Fe-oxo团簇的直接光激发在引发反应中起重要作用。此外，发现作为典型的两电子氧化反应的2-丙醇氧化反应的速率几乎不受CoO _x沉积的影响，表明CoO _x充当唯一的空穴俘获位点，并且更优先地催化这四个-电子氧化反应比二电子氧化反应更像WOR。