An Efficient, Visible Light Driven, Selective Oxidation of Aromatic Alcohols and Amines with O₂ Using BiVO₄/g-C₃N₄ Nanocomposite: A Systematic and Comprehensive Study toward the Development of a Photocatalytic Process

Abstract

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.

The Design of a New Cobalt Sulfide Nanoparticle Implanted Porous Organic Polymer Nanohybrid as a Smart and Durable Water‐Splitting Photoelectrocatalyst

“…[41] The high-resolution N1sX PS peak appearing at 398.9 eV could be assigned to the presence of the mono-functional symmetrical nitrogen group on POP surface, supplying additional evidence for the formation of aC o-N x bond which is beneficial in improving electrocatalytic activity (Figure 6f). [42][43][44][45] The onset overpotential of the photocurrent of CoS x @POP film is approximately 92 mV versus RHE.T he photocurrentd ensity of the pristine Co 3 O 4 and CoS x is not high with the value of ca.À1.5 andÀ2.5 mA cm À2 at 0Vversus RHE, whichi sq uite similar to each other in terms of over potential. Similarly,t he positive displacement in the binding energies in the N1Ss pectrum of CoS x @POP compared with the bare POP demonstrated the interaction between the N-rich POP and cobalt sulfide nanoparticles which builds a" bridge"f or the charge transfer between POP and Co 9 S 8 (Figure 6f).…”

“…All the photocurrents exhibited ar eductive photocurrent, which is attributed to the PEC water reduction. [42][43][44][45] The onset overpotential of the photocurrent of CoS x @POP film is approximately 92 mV versus RHE.T he photocurrentd ensity of the pristine Co 3 O 4 and CoS x is not high with the value of ca.À1.5 andÀ2.5 mA cm À2 at 0Vversus RHE, whichi sq uite similar to each other in terms of over potential. However, after grafting on the surface of the POP,t he biphasic composite system showed enhanced current density with lowering of the over potential to 0.18 and 0.25 Vf or Co 3 O 4 @POP and CoS x @POP respectively.…”

2D/2D Heterojunctions for Catalysis

“…After the photoexcitation of semiconductor‐based catalysts, electron–hole pairs are produced and utilized for redox reactions in organic synthesis. During the reaction process, besides photogenerated electron/hole, various reactive species (such as hydroxyl, superoxide, and oxyhydoxyperoxide radicals) may be formed through capturing electron scavengers (such as oxygen) by photogenerated electrons for various reactions, such as selective reduction, oxidation, CH activation, and CC or NN coupling reactions . Among the developed catalysts for light‐driven organic synthesis, 2D/2D heterostructures show great potential for enhancing reaction efficiency and developing valuable light‐driven organic transformation routes by using the photogenerated charge carriers at the interface as redox reagents or initiators.…”

NiO and Co3O4 co-doped g-C3N4 nanocomposites with excellent photoelectrochemical properties under visible light for detection of tetrabromobisphenol-A

“…g-C 3 N 4 -based nanocomposite, which is a newly developed novel photoelectron nanocomposite, can be used as an electron mediator for effective separation of photo-generated electronhole pairs at the junction interface. 17 Meanwhile, g-C 3 N 4 -based nanocomposites have also exhibited signicantly improved optical and electrical activities, [18][19][20] making it one of the most promising materials for the photoelectrochemical sensing method. Therefore, many researchers have made signicant efforts to improve the photoelectrochemical activity of g-C 3 N 4 by coupling it with other semiconductors, metals or carbon materials.…”