Carbon nitrides, with feasibility of tailored band gap via suitable nanoarchitectonics, are deemed as best catalysts amongst existing materials, especially for HER, OWS, COR, NRR, water oxidation, pollutant removal, and organocatalysis.

An n-p type homostructural metal-free graphitic carbon nitride (g-C₃N₄) semiconductor is designed and developed for pollutant abatement and energy storage application. The successful grafting of vibrio-like morphology-based g-C₃N₄ by 2, 5-Thiophenedicarboxylic acid (TDA) molecule and the development of amide-type linkage substantiated the prosperous uniting of g-C₃N₄ with organic TDA moiety is demonstrated. An extended π-conjugative TDA grafted g-C₃N₄ exhibited band gap tunability with broadband optical absorbance in the visible region. Mott-Schottky analysis exhibited the formation of n-p type homostructural property. As a result, obtained TDA grafted g-C₃N₄ has extended π-conjugation, high surface area and adequate separation of charge carriers. The change in the photocatalytic performance of grafted g-C₃N₄ is inspected for degradation of acid violet 7 (AV 7) dye under visible light irradiation. The charge storage capacity of grafted g-C₃N₄ was additionally assessed for supercapacitive behaviour. The charge capacitive studies of grafted g-C₃N₄ exhibited the areal capacitance of 163.17 mF cm⁻² and robust cyclic stability of 1000 cycles with capacity retention of 83%.

Vanadium oxides (V_xO_y) are classic “smart functional materials” used in a wide array of thermochromic, electronic, and catalytic applications. Specifically, vanadium dioxide (VO₂) class nanomaterials are of enormous interest due to their unique first order reversible metal-insulator phase transition (MIT) behavior accompanied by a structural phase transition, inducing dramatic changes in electrical and optical properties with large lattice deformation. To date, a plethora of reports exemplifying the MIT characteristics of VO₂, synthetic methods of VO₂, and modulating VO₂ phase transition temperatures (T_c) have been published. In this Tutorial Review, we present an overview on the fundamentals of the VO₂ band structure and principles of MIT and outline various reported synthetic approaches for VO₂ thin films, including dimensionally oriented VO₂ nanostructures. Discussion on recent trends in VO₂ applications, challenges in VO₂ synthesis, and future perspectives are also elaborated in detail.

Molecular engineering of graphitic carbon nitride (g-C₃N₄) is achieved by the copolymerization of π-conjugated phenyl urea, melamine, and urea.