Concurrent Synthesis of Functional SnO2/SnO Composite for Proton Conductive Sensor and Photo-Catalytic Treatment

Abstract

The hybrid materials have great significance in gas detection, photocatalysis and humidity sensing. In this paper, the SnO2/SnO material was successfully obtained by annealing Sn6O4(OH)4 at 350°C. The Sn6O4(OH)4 sample was synthesized by the co-precipitation method. The XRD analysis confirmed the formation of SnO2 and SnO phases and XPS analysis validated the results of XRD analysis (presence of the Sn2+ and Sn4+ states). The N2 adsorption-desorption isotherm revealed the mesoporous characteristic of the material along with 41.386 m2 g−1 BET surface area and 3.794 nm average pore diameter. As a sensing application, a sensor based on SnO2/SnO material was fabricated on the interdigitated electrodes and investigated under combined atmospheres of humidity levels (11%RH—33%–95%RH—11%RH) and ammonia (200–1200 ppm). The response and recovery times for the maximum response (under 11%RH–95%RH—11%RH and 1200ppm NH3) were 7 s and 26 s, respectively. The experimental observations confirmed that the resistance of the sensor depends on the concentration of H2O and NH3, both form the conjugate acid-base pair and which is responsible for the response of the sensor. Moreover, SnO2/SnO material as a catalyst possessed the good results for the degradation of MB (96%) and MO (84%) under visible light source.