Abstract Co3O4 imbedded g-C3N4 (Co3O4/g-C3N4) heterojunction photocatalysts were synthesized via initial dissolution of C, N and Co organic precursors in aqueous phase, subsequent evaporation of water and final thermopolymerization. This facile aqueous-induced complexation of organic precursors guaranteed that Co3O4 was homogeneously dispersed in g-C3N4 matrix even if the mass loading of Co3O4 reached up to 0.3–3 wt %. The as-constructed Co3O4/g-C3N4 composites were applied in visible-light-driven hydrogen evolution for the first time in which the mass loading of Co3O4 was optimized at 1 wt %, achieving a maximal hydrogen evolution rate of 50 μmol/h/g, as higher as 5 times than those of pure g-C3N4 and Co3O4. The enhanced photocatalytic activity of Co3O4/g-C3N4 composites was originated from well-established p-n heterojunctions when certain amount of p-type Co3O4 nanoparticles were introduced and highly dispersed into n-type g-C3N4 matrix. The Co3O4/g-C3N4 p-n heterojunctions effectively retard the recombination of photoinduced electron-hole pairs, promote charge separation, extend visible light absorption range and finally improve photocatalytic hydrogen evolution activity and stability. As a result, this facile, effective, green and universal strategy opens up new horizons to realize high dispersion of metal oxides in g-C3N4 matrix and to achieve higher performance in photocatalytic activity.

中文翻译：

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Co3O4 嵌入 g-C3N4 异质结光催化剂用于可见光驱动的析氢

摘要 Co3O4 嵌入g-C3N4 (Co3O4/g-C3N4) 异质结光催化剂是通过C、N 和Co 有机前体在水相中的初始溶解、随后的水蒸发和最终热聚合合成的。即使 Co3O4 的质量负载达到 0.3-3 wt%，这种有机前驱体的水诱导络合也能保证 Co3O4 均匀分散在 g-C3N4 基质中。所构建的 Co3O4/g-C3N4 复合材料首次应用于可见光驱动的析氢，其中 Co3O4 的质量负载优化为 1wt%，最大析氢速率为 50 μmol/h/ g，比纯 g-C3N4 和 Co3O4 高 5 倍。Co3O4/g-C3N4 复合材料增强的光催化活性源于当一定量的 p 型 Co3O4 纳米颗粒被引入并高度分散到 n 型 g-C3N4 基体中时，已经建立的 pn 异质结。Co3O4/g-C3N4 pn异质结有效地延缓了光致电子-空穴对的复合，促进了电荷分离，扩大了可见光吸收范围，最终提高了光催化析氢活性和稳定性。因此，这种简便、有效、绿色和通用的策略为实现金属氧化物在 g-C3N4 基体中的高度分散和实现更高的光催化活性开辟了新的视野。Co3O4/g-C3N4 pn异质结有效地延缓了光致电子-空穴对的复合，促进了电荷分离，扩大了可见光吸收范围，最终提高了光催化析氢活性和稳定性。因此，这种简便、有效、绿色和通用的策略为实现金属氧化物在 g-C3N4 基体中的高度分散和实现更高的光催化活性开辟了新的视野。Co3O4/g-C3N4 pn异质结有效地延缓了光致电子-空穴对的复合，促进了电荷分离，扩大了可见光吸收范围，最终提高了光催化析氢活性和稳定性。因此，这种简便、有效、绿色和通用的策略为实现金属氧化物在 g-C3N4 基体中的高度分散和实现更高的光催化活性开辟了新的视野。