Ultrafast Charge Transfer Dynamics in Multifaceted Quaternary Te–MoTe₂–MoS₂/ZnO S-Scheme Heterostructured Nanocatalysts for Efficient Green Hydrogen Energy

Abstract

Sustainable H 2 energy generation through water splitting prevalently demands systematically designed multifaceted state-of-the-art catalysts. Herein, unique Te–MoTe 2 –MoS 2 /ZnO heterostructured nanocatalysts were engineered hydrothermally for photo-/electro-/photoelectrochemical functionalities probed to ascertain the catalytic efficiency toward H 2 production. Optimized 2.5% Te–MoTe 2 –MoS 2 /ZnO (2.5TMMZ) heterojunctions were performed at an applicable standard with a H 2 production rate of 5.2 (mmol/g cat )/h at 41% AQY during photochemical experiments. Fs-TAS studies confirmed the delayed lifetime of active charge carriers at shallow and deep trap sites in the Te–MoTe 2 –MoS 2 /ZnO heterostructure. Electrochemical studies corroborated the remarkable HER and OER activities of 2.5TMMZ with −0.51 and 0.76 V overpotentials. Photoelectrochemical investigations deciphered the potential of 2.5TMMZ as it yielded nearly 3-fold higher photocurrent density than ZnO. To achieve equilibrium between conductivity–stability of the catalytic system, Te/S edge sites in Te–MoTe 2 –MoS 2 exhibited higher affinity toward H + adsorption, whereas the ZnO end of the catalyst took care of photosensitization as demonstrated via optoelectronic and theoretical characterizations alongside S-scheme mechanism.