The nature of a built-in electric field within supported metal catalysts plays a crucial role in regulating gas adsorption and electron transfer during the gas-sensing process.Herein,we found an electron-supply redepl...The nature of a built-in electric field within supported metal catalysts plays a crucial role in regulating gas adsorption and electron transfer during the gas-sensing process.Herein,we found an electron-supply redeployment phenomenon involving the reversal of direction of a built-in electric field between the metal palladium species and the outer S atoms in ZnS,resulting in a marked hydrogen sensing difference.It was found that Pd nanoparticles embedded into Pd NP-ZnS can induce spontaneous electron transfer from S atoms to Pd species to generate an electron-deficient sulfur(S(2-δ)-)surface.Conversely,atomically dispersed Pd species(Pd_(1)-ZnS)prefer to generate electron-rich sulfur(S^((2+δ)-))sites and thus reverse the built-in electric field.Theoretical calculations demonstrate that the electron-rich S(S^((2+δ)-))surface can reduce the occupancy of antibonding orbitals in the S-Hads bond and enhance the bond energy of S-Hads,thus increasing the adsorption of hydrogen.Additionally,in situ Raman,ex situ X-ray photoelectron spectroscopy and DFT analysis demonstrate that S^((2+δ)-)sites in Pd_(1)-ZnS samples can undergo strong electron transfer with hydrogen during the sensing process.Ultimately,Pd_(1)-ZnS sensors exhibit extremely high response values(9.66/20 ppm)and fast response recovery times(5.1 s/1.8 s to 400 ppm)for hydrogen gas at a working temperature of 170℃.展开更多
基金supported by the National Natural Science Foundation of China(62271299)Shanghai Sailing Program(22YF1413400).
文摘The nature of a built-in electric field within supported metal catalysts plays a crucial role in regulating gas adsorption and electron transfer during the gas-sensing process.Herein,we found an electron-supply redeployment phenomenon involving the reversal of direction of a built-in electric field between the metal palladium species and the outer S atoms in ZnS,resulting in a marked hydrogen sensing difference.It was found that Pd nanoparticles embedded into Pd NP-ZnS can induce spontaneous electron transfer from S atoms to Pd species to generate an electron-deficient sulfur(S(2-δ)-)surface.Conversely,atomically dispersed Pd species(Pd_(1)-ZnS)prefer to generate electron-rich sulfur(S^((2+δ)-))sites and thus reverse the built-in electric field.Theoretical calculations demonstrate that the electron-rich S(S^((2+δ)-))surface can reduce the occupancy of antibonding orbitals in the S-Hads bond and enhance the bond energy of S-Hads,thus increasing the adsorption of hydrogen.Additionally,in situ Raman,ex situ X-ray photoelectron spectroscopy and DFT analysis demonstrate that S^((2+δ)-)sites in Pd_(1)-ZnS samples can undergo strong electron transfer with hydrogen during the sensing process.Ultimately,Pd_(1)-ZnS sensors exhibit extremely high response values(9.66/20 ppm)and fast response recovery times(5.1 s/1.8 s to 400 ppm)for hydrogen gas at a working temperature of 170℃.
