Smart chemical sensor and active photo-catalyst for environmental pollutants

► Newly synthesized ZnO–CeO 2 nanoparticles. ► Low temperature synthesis. ► High sensitivity. ► Efficient photocatalyst. ► Eco-friendly chemi-sensor and photocatlyst. In this contribution, nanoparticles composed of ZnO–CeO 2 were synthesized by simple and efficient low temperature process and employed for the development of effective chemical sensor as well as photo-catalyst for the removal of environmental contaminants. Field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR) were used to confirmed the morphology and structure of the synthesized ZnO–CeO 2 nanomaterial which revealed well crystalline aggregated nanoparticles with average diameters of ∼50 ± 10 nm. The composition of the nanoparticles was obtained by using EDS spectroscopy while the optical property was measured using UV–vis absorption spectrum. Photocatalytic degradation of acridine orange (AO) and methylene blue (MB) dyes has been carried out using ZnO–CeO 2 nanoparticles, which showed 92.1% degradation for AO and 80.7% degradation for MB in 170 min of irradiation time. The analytical performance of ZnO–CeO 2 nanoparticles fabricated ethanol sensor exhibited higher sensitivity (2.1949 μA cm −2 mM −1) as well as lower detection limit (0.6 ± 0.05 mM) in short response time.