LAUSR

Traditionally, sol–gel processing of metal oxides using organometallic precursors is expensive, nonaqueous, and complicated when it comes to two-or-more dissimilar metal oxides. Herein, we report a versatile epoxide-assisted non-organometallic, aqueous, and inexpensive synthesis route of developing Cu/SnO2 xerogels and their use as efficient formaldehyde (FA) gas sensors. The route utilizes easy to handle salts as precursors (tin and copper chlorides, in the present case) and organic epoxide (propylene oxide) as a gelation agent, which led to highly porous web matrix of Cu/SnO2. The obtained Cu/SnO2 xerogels, with 0–2  mol% Cu doping, were analyzed using XRD, Fourier transform infrared, UV–Vis, FE-SEM, TEM/HRTEM, and EDAX. As-developed xerogels showed their versatility in physico-chemical as well as FA gas sensing properties. By proper Cu-doping level in SnO2 matrix, the reduction in sensor operating temperature (325–275 °C) and enhancement in the gas response (S = 50–96%) are chronicled. The effects of gas sensing are represented by an epoxy-assisted Cu/SnO2 sol–gel process and the subsequent morphological and structural properties. The very simple and straight forward route for mixed metal oxides synthesis. Need metal salts as precursors in aqueous solution, hence remove the necessity of organometallic precursors. Cu/SnO2 with 1 mol% doping level exhibited excellent gas sensing ability of 96% to formaldehyde at 275 °C operating temperature. For the same sensor material, the operating temperature got reduced from 325 °C to 275 °C. The measurements for 4 months (with an interval of 10 days) showed ~84% of its initial sensitivity. The very simple and straight forward route for mixed metal oxides synthesis. Need metal salts as precursors in aqueous solution, hence remove the necessity of organometallic precursors. Cu/SnO2 with 1 mol% doping level exhibited excellent gas sensing ability of 96% to formaldehyde at 275 °C operating temperature. For the same sensor material, the operating temperature got reduced from 325 °C to 275 °C. The measurements for 4 months (with an interval of 10 days) showed ~84% of its initial sensitivity.