Facet effect on diverse WO3 morphologies and ideal work function for ppb-level triethylamine detection

Tungsten oxides with different crystal facet ratios were successfully prepared through one-spot solvothermal approach using alcohol solvents with different C chains accompanied by annealing treatment. The sensing performances for detecting triethylamine have been systematically investigated among the as-obtained WO3 samples. Benefiting from the unique microstructure with bimodal pores, the highest work function for the low-intensity ratio of the (002) WO3 facet, the smallest average crystallites sizes and abundant grain boundaries, the sensor based on WO3 microflowers assembled by tiny nanoparticles exhibits appealing sensing performance including high response, excellent selectivity, rapid response/recovery time (3 s/5 s) to 1 ppm triethylamine and extremely low detection limitation (200 ppb) at 325 °C.