Near-infrared, eco-friendly ZnAgInSe quantum dots-sensitized graphene oxide-TiO2 hybrid photoanode for high performance photoelectrochemical hydrogen generation

Colloidal semiconductor quantum dots (QDs) are promising building-blocks for the manufacture of cost-effective photoelectrochemical (PEC) cells towards efficient solar-to-hydrogen conversion. Nevertheless, the state-of-the-art QDs-based PEC systems still suffer from the frequent utilization of highly toxic elements in QDs (Cd and Pb), hindering their future practical applications and potential commercialization. Here, we report a PEC device fabricated using eco-friendly, near-infrared (NIR) ZnAgInSe (ZAISe) QDs and hybrid TiO2/graphene oxide (GO) film. Based on the synergistic effect of QD's broad light absorption and excellent charge extraction/transport properties of TiO2/GO film, as-assembled QDs-photoanode exhibits an outstanding saturated photocurrent density of ~6.7 mA/cm2 with good stability under standard 1 sun illumination. The introduction of functional GO can lead to the reduced charge transfer resistance, suppressed charge recombination, and enhanced electron transport within the QDs-TiO2 photoanodes. The results offer a facile and effective method to enhance the performance of environmentally friendly QDs-based PEC devices and shed light on the development of low-cost, “green” and high-efficiency solar-to-hydrogen conversion system