Improving the triethylamine sensing performance based on debye length: A case study on α-Fe2O3@NiO(CuO) core-shell nanorods sensor working at near room-temperature

•Porous α-Fe2O3 nanorods are directly grew on Al2O3 substrates.•The construction of α-Fe2O3@NiO(CuO) core-shell nanorods heterostructure by PLD is highly controllable.•The PN depletion layer formed at the core-shell nanorod interface can enhance the TEA sensor performance.•Debye length is proved to be a critical reference criterion for further optimizing the p-type shell thickness.