Facile controlled synthesis of bifunctional ZnO nanoparticles for application as a high-performance self-powered UV photosensor and highly selective vapor sensor.

[Display omitted] • Facile synthesis of WZ structure ZnO NPs of size 10–20 nm via chemical route at room temperature. • Fabrication of self-powered photosensor in Schottky contact (Au/ ZnO NPs/FTO) configuration. • 1.5x104 on/off ration, 649 mA/W responsivity (R(λ)), external quantum efficiency (EQE) 217 % and detectivity (D) 2.4x 1013 Jones at 0 V. • Fabrication of MSM structure for gas sensors and demonstration of maximum sensitivity of ZnO NPs towards propenol vapor with possible mechanism. ZnO has unique multifunctional and morphological properties, and has received significant attention in the field of next-generation sensors and photonic devices. Herein, we report bifunctional ZnO nanoparticles (NPs) used for the selective detection of hazardous gases and self-powered photo response. ZnO nanoparticles with a wurtzite structure and particle size in the range of 10–20 nm were synthesized and fully characterized. ZnO NPs were explored as selective self-powered UV light (370 nm) photosensors and gas sensors. The photoresponse upon illumination with 370-nm light exhibited self-power behavior with an on/off ratio of 1.5x 104, responsivity (R(λ)) of 649 mA/W, external quantum efficiency (EQE) of 217%, and detectivity (D) of 2.4 × 1013 Jones at a bias voltage of 0 V. Maximum sensitivities of 211% and 96% were observed for propanol and chloroform, respectively, among the different gas environments, with quick response, short recovery times, and good repeatability. A possible mechanism has been proposed using the morphology, structural, and electrical characterization results. Thus, our study opens a path for synthesis of multifunctional nanomaterials and their exploration for multiple applications. [ABSTRACT FROM AUTHOR]