Scalable Core–Shell MoS₂/Sb₂Se₃ Nanorod Array Photocathodes for Enhanced Photoelectrochemical Water Splitting

Photoelectrochemical (PEC) hydrogen generation is a promising solar energy harvesting technique to address the concerns about the ongoing energy crisis. Antimony selenide (Sb 2 Se 3 ) with van der Waals‐bonded quasi‐1D (Q1D) nanoribbons, for instance, (Sb 4 Se 6 ) n , has attracted considerable interest as a light absorber with Earth‐abundant elements, suitable bandgap, and a desired sunlight absorption coefficient. By tuning its anisotropic growth behavior, it is possible to achieve Sb 2 Se 3 films with nanostructured morphologies that can improve the light absorption and photogenerated charge carrier separation, eventually boosting the PEC water‐splitting performance. Herein, high‐quality Sb 2 Se 3 films with nanorod (NR) array surface morphologies are synthesized by a low‐cost, high‐yield, and scalable close‐spaced sublimation technique. By sputtering a nonprecious and scalable crystalline molybdenum sulfide (MoS 2 ) film as a cocatalyst and a protective layer on Sb 2 Se 3 NR arrays, the fabricated core–shell structured MoS 2 /Sb 2 Se 3 NR PEC devices can achieve a photocurrent density as high as −10 mA cm −2 at 0 V RHE in a buffered near‐neutral solution (pH 6.5) under a standard simulated air mass 1.5 solar illumination. The scalable manufacturing of nanostructured MoS 2 /Sb 2 Se 3 NR array thin‐film photocathode electrodes for efficient PEC water splitting to generate solar fuel is demonstrated.