Hollow SnO2/Zn2SnO4 cubes with porous shells towards n-butylamine sensing and photocatalytic applications

The cube-shaped SnO2/Zn2SnO4 composites with hollow structure were synthesized using a facile solvothermal method followed by calcinations and applied as hazardous gas sensors and photocatalysts for the degradation of three different types of dyes. As-synthesized SnO2/Zn2SnO4 hollow cubes with a wall thickness of about 80 nm possessed plenty of pores, and average pore size was about 3.0 nm. The sensor based on SnO2/Zn2SnO4 hollow cubes displayed the response of 77.2 towards 100 ppm n-butylamine at the optimal operating temperature of 300 °C, which was 1.43-times larger than that of SnO2/Zn2SnO4 solid cubes and improved in comparison with previously reported values. Additionally, it exhibited great selectivity and long-term stability. For the photocatalytic performance, SnO2/Zn2SnO4 hollow cubes showed faster photocatalytic degradation efficiency towards the common cationic dye methylene blue, the anionic dye methyl orange and the neutral dye eriochrome black T than SnO2/Zn2SnO4 solid cubes under simulated sunlight. These excellent properties were originated from the porous surface, cube/cube junction and the hollow interior structure, which was highly advantageous to the mass transportation and reagent diffusion. It's worth mentioning that great reproducibility highlight the potential applications of the SnO2/Zn2SnO4 hollow cubes in monitoring inflammable and toxic gases, and photocatalytic degradation of pollution.