Growth of AgI semiconductors on tailored 3D porous TiC MXene/graphene oxide aerogel to develop sensitive and selective "signal-on" photoelectrochemical sensor for HS determination.

Long term exposure to hydrogen sulfide (HS) even in low concentration poses a serious threat to human health and the ecosystem, pointing to the significance for its effective supervision. In this study, we report a sensitive and selective "signal-on" photoelectrochemical (PEC) sensor for the determination of toxic HS in aqueous solution by in situ growth of AgI semiconductors on tailored three-dimensional (3D) porous TiC MXene/graphene oxide aerogel (MGA). Our research demonstrated that the resultant MGA with the starting feeding mass ratio of MXene and graphene oxide (GO) of 1:8 (MGA) possessed the most excellent PEC performance after the growth of AgI semiconductors than their monomers (TiC MXene and GO) and the MGAs with other starting feeding mass ratio. Such designed PEC sensor based on MGA/AgI heterojunction showed dramatically strengthened PEC responses with increasing concentrations of S. Correspondingly, a wide linear range of 5 nM-200 μM, a low limit of detection of 1.54 nM (S/N = 3), and exclusively unique selectivity have been achieved. Our research illustrates that the PEC sensor designed with tailored MGA constitutes is an effective pathway to enhance the overall sensing performance, which will envision to boost more efforts for advanced 3D porous aerogel using in PEC sensors.