Thermal Oxidation Strategies for the Synthesis of Binary Oxides and their Applications

Abstract

Binary oxides constitute an outstanding class of functional materials with potential applications in many fields such as catalysis, gas sensing, field emission, solar cells, photodetection, etc. Due to the difference in their physical/chemical properties, different oxides have been explored for different applications. For examples, SnO2, Cr2O3 and ZnO are being explored for gas sensing due to their high adsorption capacity for volatile gases, ZnO, Cu2O etc. are being explored in solar cells because of high adsorption coefficient in UV/visible region and so on. Various techniques are available for synthesis of binary oxides and tuning their properties. Most of the physical or chemical synthesis techniques are expensive, need high cost instruments and produces hazardous chemical waste. We need a simple, cost effective and ecofriendly techniques for the synthesis of binary oxides.

In present work, a simple and facile thermal oxidation strategy has been employed for the synthesis of various binary oxides (Cu2O, GeO2 and ZnO). For example, CuO nanorods are obtained when Cu is heated around ~ 500 oC, which then heated in Ar atmosphere to obtain a film of porous Cu2O. Similarly, GeO2 with different morphologies and green-luminescent ZnO are obtained by controlling the reaction parameters. These oxides have then been explored for various applications including white light phosphors, catalysis for the degradation of dyes and non-contact thermometry. Overall, we present a thermal oxidation strategy for the synthesis of various binary oxides and explore potential applications in various fields.