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

Sustainable H₂ energy generation through water splitting prevalently demands systematically designed multifaceted state-of-the-art catalysts. Herein, unique Te-MoTe₂-MoS₂/ZnO heterostructured nanocatalysts were engineered hydrothermally for photo-/electro-/photoelectrochemical functionalities probed to ascertain the catalytic efficiency toward H₂ production. Optimized 2.5% Te-MoTe₂-MoS₂/ZnO (2.5TMMZ) heterojunctions were performed at an applicable standard with a H₂ 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-MoTe₂-MoS₂/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-MoTe₂-MoS₂ 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.