Crystal Phase‐Dependent One‐Pot Synthesis of SrTiO 3 :Al for High‐Efficiency Photocatalytic Overall Water Splitting

Aluminum‐doped strontium titanate (STO:Al) has attracted great attention due to high photocatalytic overall water splitting (POWS) activity. In this study, STO:Al catalysts are successfully synthesized via a one‐pot strategy using three types of TiO 2 (rutile, anatase, and P25) with investigating the influence of these three crystal phases on photocatalytic performance of synthesized STO:Al. Among the samples, STO‐A (derived from anatase) performs superior activity, which is attributed to its low defect concentration, excellent hydrophilic property, enhanced optical absorption, and long carriers lifetime. The specific synthesis pathway is elucidated through thermogravimetric analysis ‐ differential scanning calorimetry analysis. In addition, commercially available anatase of different sizes are employed to optimize the synthesis. Of these, STO‐A60(prepared from 60 nm anatase) demonstrated top activity in POWS, with solar‐to‐hydrogen (STH) up to 0.56%. This study presents a practical approach to address the challenge associated with high cost and performance inconsistency of SrTiO 3 :Al arising from commercial SrTiO 3 . Additionally, outdoor field tests are conducted with an STH efficiency exceeding 0.45%, which is promising in large‐scale application.