“…20 Despite its advantages, bare g-C 3 N 4 appears to be restricted in terms of low photocatalytic efficiency and applicability because of poor light absorption and fast recombination of photoexcited charge carriers. To overcome these shortcomings, researchers have endeavoured to develop new approaches, including protonation, polymerization, 21 increasing surface area, 22 doping, 23 controlling morphology, 24 and coupling with other semiconducting materials 25 to enhance charge transfer and separation, thus improving the photocatalytic activity of g-C 3 N 4 .…”