Promoting Visible Light Generation of Hydrogen Using a Sol–Gel-Prepared MnCo(2)O(4)@g-C(3)N(4) p–n Heterojunction Photocatalyst

[Image: see text] The production of hydrogen using a new type of heterogeneous photocatalyst under visible light is considered a remarkable essential pathway for sustainable, pure energy not only on the laboratory scale but also on a bigger scale. Hence, a new nanocomposite of mesoporous MnCo(2)O(4), g-C(3)N(4), and MnCo(2)O(4)@g-C(3)N(4) was produced utilizing a sol–gel method with variable MnCo(2)O(4) contents. The crystal structure of MnCo(2)O(4) was effectively confirmed by the X-ray diffraction pattern and integrated onto the g-C(3)N(4) structure. The MnCo(2)O(4) nanoparticles were displayed as spherical particles by TEM images and dispersed in a uniform way inside the g-C(3)N(4) nanosheet. The synthesized nanocomposites in the form of MnCo(2)O(4)@g-C(3)N(4) were examined as a new effective photocatalyst against glycerol as a source for H(2) production with visible light. The MnCo(2)O(4) contents indicated a corroborative impact for the photocatalytic action related to the H(2) production process. A maximum H(2) production molecular value was observed (21,870 μmol·g(–1)·h(–1)) for a 1.5 wt % MnCo(2)O(4)@g-C(3)N(4) nanocomposite as a considerable increase in its photocatalytic activity. The yields of H(2) are ∼55 and 23 times higher than those of g-C(3)N(4) and MnCo(2)O(4), respectively. Up to five times cycles of visible lighting were the maximum number of repeated cycles by which the 1.5 wt % MnCo(2)O(4)@g-C(3)N(4) product showed higher stability and durability.