Ultrafast Hole Trapping in Te‐MoTe<sub>2</sub>‐MoSe<sub>2</sub>/ZnO S‐Scheme Heterojunctions for Photochemical and Photo‐/Electrochemical Hydrogen Production
Syed Asim Ali, Tokeer Ahmad
Abstract
Abstract Te‐MoTe 2 ‐MoSe 2 /ZnO S‐scheme heterojunctions are engineered to ascertain the advanced redox ability in sustainable HER operations. Photo‐physical studies have established the steady state transfer of photo‐induced charge carriers whereas an improved transfer dynamics realized by state‐of‐art ultrafast transient absorption and irradiated‐XPS analysis of optimized 5wt% Te‐MoTe 2 ‐MoSe 2 /ZnO heterostructure. 2.5, 5, and 7.5wt% Te‐MoTe 2 ‐MoSe 2 /ZnO photocatalysts (2.5MTMZ, 5MTMZ and 7.5MTMZ) exhibited 2.8, 3.3, and 3.1‐fold higher HER performance than pristine ZnO with marvelous apparent quantum efficiency of 35.09%, 41.42% and 38.79% at HER rate of 4.45, 5.25, and 4.92 mmol/g cat /h, respectively. Electrochemical water splitting experiments manifest subdued 583 and 566 mV overpotential values of 2.5MTMZ and 5MTMZ heterostructures to achieve 10 mA cm −2 current density for HER, and 961 and 793 mV for OER, respectively. For optimized 5MTMZ photocatalyst, lifetime kinetic decay of interfacial charge transfer step is evaluated to be 138.67 ps as compared to 52.92 ps for bare ZnO.