Superior room temperature ammonia gas sensing of copper selenide nanoflowers

Facile wet chemical synthesis was utilized to synthesize nanoflowers of copper selenide (CuSe) that exhibited exceptional room temperature ammonia (NH 3 ) gas sensing capability. Observations of surface morphology revealed the presence of petal -like structures arranged in a flower-like pattern. The layered materials have been analyzed for their crystalline structure, phase, composition, and band gap by utilizing X-ray diffraction, Transmission Electron Microscopy, Raman spectroscopy, and energy -dispersive X-ray spectroscopy, UV-Vis, respectively. At ambient conditions, CuSe nanoflowers-based sensor demonstrated exceptional sensitivity, reaching up to 79% (200 ppm NH 3 ) with short response and recovery time of 12.9 s and 6.3 s, respectively, at 5 ppm gas concentration. The sensor exhibited rapid response and recovery times, a broad concentration range, long-term stability over extended periods, exceptional specificity towards NH 3 , and good repeatability owing to its distinct flower -shaped structures assembled in thin layers. Density Functional Theory simulations were conducted to investigate the interactions between NH 3 and CuSe. Our findings revealed an increase in the adsorption energy of NH 3 on CuSe, indicating a stronger binding affinity. We observed a higher charge transfer from CuSe to NH 3 , which suggests an increase in conductivity. This increase in conductivity enhances the superior sensing capability observed in the experimental results.