Visvesvaraya Technological University

About: Visvesvaraya Technological University is a education organization based out in Belgaum, Karnataka, India. It is known for research contribution in the topics: Cloud computing & Wireless sensor network. The organization has 1363 authors who have published 1345 publications receiving 10333 citations. The organization is also known as: VTU.

Graphitic carbon nitride (g–C3N4)–based metal-free photocatalysts for water splitting: A review

Abstract: A variety of g–C3N4–based metal-free photocatalysts for H2 generation including structurally manipulated g-C3N4, g–C3N4–doped with non-metallic elements and molecules, hetero-junctions of g-C3N4 with carbonaceous materials, polymers as well as SiC and g–C3N4–based iso-type or homo-junctions are considered. Innumerable strategies have been attempted to enhance H2 evolution rate of g–C3N4–derived metal-free photocatalysts compared to pure g-C3N4. Furthermore, challenges in this area are yet to be tackled to resolve the issues low efficiency, low stability and dependence on noble metal co-catalysts for increasing the product yield and reduction in redox capability by narrowing the band gap. This review attempts to cover the latest developments, especially in the area of graphitic carbon nitride (g–C3N4)–based metal-free photocatalysts for H2 generation.

Polymeric graphitic carbon nitride (g-C3N4)-based semiconducting nanostructured materials: Synthesis methods, properties and photocatalytic applications.

Abstract: In recent years, various facile and low-cost methods have been developed for the synthesis of advanced nanostructured photocatalytic materials. These catalysts are required to mitigate the energy crisis, environmental deterioration, including water and air pollution. Among the various semiconductors explored, recently novel classes of polymeric graphitic carbon nitride (g-C3N4)-based heterogeneous photocatalysts have established much greater importance because of their unique physiochemical properties, large surface area, low price, and long service life, ease of synthesis, product scalability, controllable band gap properties, low toxicity, and high photocatalytic activity. The present comprehensive review focuses on recent achievements in a number of facile chemical synthesis methods for semiconducting polymeric carbon nitrides and their heterogeneous nanohybrids with various dopants, nanostructured metals, metal oxides, and nanocarbons, as well as the parameters influencing their physiochemical properties and photocatalytic efficiency, which are discussed with reference to various catalytic applications such as air (NOx) purification, wastewater treatment, hydrogen generation, CO2 reduction, and chemical transformation. The mechanisms for the superior photocatalytic activity of polymeric g-C3N4-based heterogeneous photocatalysts are also discussed. Finally, the challenges, prospects, and future directions for photocatalytic polymeric g-C3N4-based semiconducting materials are described.

ZnO-based nanostructured electrodes for electrochemical sensors and biosensors in biomedical applications

Abstract: Fascinating properties of ZnO nanostructures have created much interest due to their importance in health care and environmental monitoring. Current worldwide production and their wide range of applications signify ZnO to be a representative of multi-functional oxide material. Recent nanotechnological developments have stimulated the production of various forms of ZnO nanostructures such as nano-layers, nanoparticles, nanowires, etc. Due to their enhanced sensing properties, improved binding ability with biomolecules as well as biological activities have enabled them as suitable candidates for the fabrication of biosensor devices in the biomedical arena. In this review, the synthesis of ZnO nanostructures, mechanism of their interaction with biomolecules and their applications as sensors in health care area are discussed considering the biosensors for molecules with small molecular weight, infectious diseases, and pharmaceutical compounds.

Low-cost synthesis of metal oxide nanoparticles and their application in adsorption of commercial dye and heavy metal ion in aqueous solution

Abstract: Metal oxide nanoparticles such as ZnO and SnO 2 with specific surface areas of 15.75 and 24.48 m 2 /g respectively were successfully synthesized by precipitation method and then employed as adsorbents for removal of Malachite Green Oxalate (MGO) and hexavalent Chromium (Cr) from aqueous solution. The nanoparticles were characterized by XRD, SEM, TEM, SAED, FT-IR and BET surface area analysis. The adsorption of MGO and Cr was achieved under different adsorbate concentration, contact time, adsorbent dosage, pH and temperature conditions. Adsorption equilibrium was studied with Langmuir and Freundlich isotherm models. Equilibrium data were best fitted with the Langmuir and Freundlich isotherm models. Kinetic studies indicated that the adsorption process follows second order kinetics and particle diffusion mechanisms are operative. Thermodynamic parameters were studied in detail to know the nature and mechanism of adsorption. The spent adsorbents were regenerated with CH 3 COOH or NaOH solutions and regenerated adsorbents showed very good adsorption efficiencies. All the above results demonstrated that metal oxide nanoparticles could be used as a possible alternative low-cost adsorbent for the efficient removal of dyes and heavy metals from aqueous solution.