ZnO: SnO2 nanocomposite efficacy for gas sensing and microbial applications

The unique characteristics of 2-dimensional hetero structure offers efficient gas sensing with high selectivity to identify gases from the interference gases which is quite difficult. In the present work, ZnO: SnO2 Nano composite clusters (NCC) is prepared. A resistive metal oxide volatile organic compound (VOC) gas sensor is fabricated with nullifying the effect of humidity by increasing temperature optimally A single-step SOL-GEL (SG) synthesis is used to prepare ZnO: SnO2 NCC with maximum Zn/Sn molar concentration ratio of 3. The morphological studies through Scanning Electron Microscopy (SEM), electrical properties due to oxygen vacancies and energy band variations of Nanocomposite are measured. The enhancement of gas sensor sensitivity due to highly mesoporous nature of the composite is observed. From the findings, the abundant mesopores in the range of 2 nm-14 nm and specific surface area of 54.2 m(2) g(-1) with the average crystal size of 14.236 nm, and polar surface area of the composite 25.9651 angstrom is achieved. When compared to bare ZnO and SnO2 gas sensors, the present gas sensor offers the higher selectivity with enhanced performance due to the mesoporous structure. Fast repeatability rate of 2200 sec at 350 degrees C to ethanol is attained and the overall selectivity of the sensor increased twice as 2.085. The NCC compound is tested firstly with micro organisms such as B. subtilis (B. S), Bacillus cereus (B. C), B. coagulans (B. C), Pseudonymous auriginosa (P. A) are considered for antimicrobial activity. From the findings, zinc stannate compound showed good efficacy towards B. cereus Gram positive and P.A gram-negative. A bacterial growth is arrested highly with B. cereus.

Automated summary

The study synthesized ZnO: SnO2 nano composite clusters through a one-step sol-gel method and increased temperature to compensate for humidity effects and improve the selectivity and performance of the gas sensor. The composite material with high mesoporous structure showed enhanced sensitivity of the gas sensor. Additionally, the composite material exhibited antimicrobial activity against certain bacteria.