A facile synthesis of Pd-doped SnO2 hollow microcubes with enhanced sensing performance

Abstract

A novel and convenient synthesis of Pd-doped SnO2 hollow microcubes (PdO–SnO2 HCs) have been achieved via successively annealing and acid etching cube-like hollow zinc hydroxystannate (ZnSn(OH)6) decorated with Pd(OH)2. The resulting PdO–SnO2 HCs possess special cube-like hollow interiors with void architectures together with a porous surface composed of nano-sized primary SnO2 nanoparticles. Utilized as the composite materials in sensors, the PdO–SnO2 HCs doping of Pd with 1.0% molar ratio (1.0 mol% PdO–SnO2) demonstrated an excellent selectivity towards ethanol in various gases at an operating temperature of 300°C, performing with a high response value of 90 along with a short response and recovery time (3s, 22s) to 200ppm ethanol. Such a superior sensing performance of the PdO–SnO2 HCs could be attributed to the synergistic interactions between the uniformly dispersed PdO and the SnO2-based hollow architectures, in which a hollow framework of SnO2 provides a large active surface area and the catalytic effect of the PdO enhances the chemisorption and dissociation of the target gas. With a simple fabrication procedure and a desirable sensing performance, this method offers a highly promising candidate for the development of special morphologies of materials for sensors.