Dual-selective detection of CO and CH_(4) based on hierarchical porous In_(2)O_(3) nanoflowers with Pd modification

The timely and effective detection of CO and CH_(4) is critical as the explosion and poisoning of them can bring serious potential risks to coal mining.In this study,combining metal oxide semiconductors with noble metals offers a promising route to achieve this target.Hierarchical porous Pd modified In_(2)O_(3) nanoflowers were prepared via two-step hydrothermal method and exhibited dual detection of CO and CH_(4) at different temperatures.The material has been characterized by a number of advanced techniques and the results indicate that Pd modified In_(2)O_(3) are hierarchical porous nanoflowers structure consisting of pores of approximately 1.8 nm in size.The sensing properties results show that the Pd modified In_(2)O_(3) based sensor exhibits temperature-dependent dual selectivity detection of CO at 280℃ and CH_(4) at 340℃.In addition,the Pd modified In_(2)O_(3) sensor display higher sensing response of CO(5.824 for 100 ppm)and CH_(4)(1.162 for 1000 ppm),fast response and recovery time,as well as good repeatability,which demonstrating the great potential for practical application.Such good gas-sensing performance are mainly attributed to the unique flower-like structure,the presence of porosity on the sample surface,and the catalytic effect of Pd.