Noble‐metal Au nanoparticles deposited on graphitic carbon nitride polymer (g‐C3N4) photocatalyst by a facile deposition–precipitation method exhibited high photocatalytic activity for hydrogen gas production under visible‐light irradiation. The Au/g‐C3N4 nanocomposite plasmonic photocatalysts were characterized by X‐ray diffraction spectroscopy, diffuse reflectance UV/Vis spectroscopy, FTIR spectroscopy, field‐emission scanning electron microscopy, high‐resolution transmission electron microscopy, selected‐area electron diffraction, X‐ray photoelectron spectroscopy, photoluminescence spectroscopy, and photoelectrochemical measurements. We studied the effect of Au deposition on the photocatalytic activity of g‐C3N4 by investigation of optical, electronic, and electrical properties. Enhanced photocatalytic activity of Au/g‐C3N4 naocomposite for hydrogen production was attributed to the synergic mechanism operating between the conduction band minimum of g‐C3N4 and the plasmonic band of Au nanoparticles including high optical absorption, uniform distribution, and nanoscale particle size of gold. The mechanism of te photocatalytic activity of the nanocomposite photocatalyst is discussed in detail. Deposition of Au nanoparticles on g‐C3N4 was optimized and it was found that 1 wt % Au‐loaded g‐C3N4 composite plasmonic photocatalyst generated a photocurrent density of 49 mA cm−2 and produced a hydrogen gas amount of 532 μmol under visible light, which were more than 3000 times higher and 23 times higher, respectively, than the values of neat g‐C3N4.

In this study, BiVO4 was prepared by a hydrothermal synthesis route in the presence of sodium dodecyl sulfate using aqueous NH3 as precipitant. g-C3N4 was prepared by a combustion method using melamine. In order to develop highly efficient photocatalyst, a heterojunction catalyst based on g-C3N4 and BiVO4 was prepared. Different amounts of BiVO4 and g-C3N4 were mixed and annealed to obtain heterojunction photocatalysts. FeVO4 and LaVO4 were also prepared for the comparative catalytic investigation. Catalysts were characterized by a series of complementary combinations of powder X-ray diffraction, thermogravimetric analysis, elemental analysis, N2 adsorption–desorption, scanning electron microscopy, transmission electron microscopy, temperature-programmed desorption of NH3 and CO2, diffuse reflectance ultraviolet visible spectroscopy, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, and photoelectrochemical studies. Catalysts were investigated in the visible light driven oxidation of benzyl alcohol, benzyl amine, and aniline with O2. In order to propose the electrons, holes, and radicals mediated reaction pathways, reactions were performed in the presence of an electron/hole/radical scavenger. Further, in order to confirm various products formed during the photocatalytic oxidation of benzyl alcohol, benzyl amine, and aniline, several model reactions were carried out. Based on the results obtained, the reaction mechanism and structure–activity relationship were established.

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Carbon nitride with tunable textural properties, chemical properties (N contents, types of N species, and dopants), and optoelectronic properties can activate and convert CO2 to useful chemicals and fuels by using various forms of energy resources.

Highly efficient and recyclable bi-functional carbon nitride for sustainable catalysis in the synthesis of cyclic and di-alkyl carbonates, quinazoline-2,4(1H,3H)-dione, and methyl oleate.