Abstract. Co3O4 nanoparticles were synthesized by a green synthesis method using bread fungus and cobalt nitrate hexahydrate as the precursors. The effects of the calcination temperature on the structure and properties of nanoparticles, and the ambient temperature on the photocatalytic reaction are discussed. The cubic structure of Co3O4 nanoparticles was obtained, and the grain size was between 14 and 19 nm at different calcination temperatures. Co3O4 calcined at 500°C shows good photocatalytic performance. Without adding any sacrificial agent and cocatalyst, the amount of hydrogen and oxygen released in 5 h were 259.4 and 135.7 μmolg − 1, respectively. The results show that, with the increase of ambient temperature, the evolution rate of hydrogen and oxygen is accelerated, and the atomic ratio of hydrogen to oxygen is close to 2:1. In addition, the Co3O4 photocatalyst has good stability. Our study provides an environmentally friendly, low-cost, and efficient method for the preparation of cobalt oxide photocatalysts with excellent performance.

中文翻译：

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绿色合成的 Co3O4 纳米颗粒作为光催化剂用于整体水分解的温度效应

摘要。以面包菌和六水硝酸钴为前驱体，通过绿色合成法合成了 Co3O4 纳米颗粒。讨论了煅烧温度对纳米颗粒结构和性能的影响，以及环境温度对光催化反应的影响。得到Co3O4纳米颗粒的立方结构，不同煅烧温度下晶粒尺寸在14～19nm之间。Co3O4 在 500°C 下煅烧显示出良好的光催化性能。在不添加任何牺牲剂和助催化剂的情况下，5 小时内释放的氢和氧量分别为 259.4 和 135.7 μmolg - 1。结果表明，随着环境温度的升高，氢和氧的析出速率加快，氢氧原子比接近2:1。此外，Co3O4 光催化剂具有良好的稳定性。我们的研究为制备性能优异的氧化钴光催化剂提供了一种环保、低成本、高效的方法。