In-situ construction of TiO2 polymorphic junction nanoarrays without cocatalyst for boosting photocatalytic hydrogen generation

There are significant challenges in developing technologies for high-yield photocatalytic hydrogen production reactions. Current photocatalytic materials face three key problems: low utilization of light, rapid recombination of photogenerated electron-hole pairs, and a limited number of active sites during photocatalytic reactions. As a result, these materials only improve one or two of the three steps involved in photocatalytic hydrogen production reactions. Consequently, achieving simultaneous multifunctional synergy to enhance the efficiency of all three processes is difficult. Here, we report an in situ dissolution-recrystallisation approach to design and fabricate a three-dimensional TiO2 rutile/anatase (AE-TiO2) array photocatalytic material for photocatalytic hydrolysis applications. It is shown that the unique 3D nanoarray structure and in situ fabrication of the AE-TiO2 homojunction with synergistic effects among the components lead to an increase in light harvesting efficiency, charge transport separation efficiency and surface active sites, which remarkably improve the photocatalytic hydrolysis performance. The prepared AE-TiO2 homojunction materials realizes a maximal photoactivity of 4 μmol cm−2·h−1, which is 39 times larger than that of pure TiO2 rutile nanorods.