A series of Ti₂O₃@TiO₂ core-shell heterojunction composite photocatalysts with different internal electric fields were synthesized using simple heat treatment methods. The synthesized Ti₂O₃@TiO₂ core-shell heterojunction composites were characterized by means of SEM, XRD, PL, UV–Vis, BET, SPV, TEM and other related analytical techniques. Tetracycline (TC) was used as the degradation target to evaluate the photocatalytic performance of the synthesized Ti₂O₃@TiO₂ core-shell heterojunction composites. The relevant test results show that the photocatalytic performance of the optimized materials has been significantly enhanced compared to Ti₂O₃, while the photocatalytic degradation rate has increased from 28% to 70.1%. After verification via several different testing and characterization techniques, the excellent catalytic performance is attributed to the efficient separation efficiency of the photogenerated charge carriers derived from the built-in electric field formed between Ti₂O₃ and TiO₂. When the recombination of electrons and holes is occupied, more charges are generated to reach the surface of the photocatalyst, thereby improving the photocatalytic degradation efficiency. Thus, this work provides a universal strategy to enhance the photocatalytic performance of Ti₂O₃ by coupling it with TiO₂ to build an internal electric field.

Sr₂TiO₄, a prominent member of the Ruddlesden–Popper (RP) perovskite family, has garnered significant interest in photocatalysis, primarily owing to its distinctive two-dimensional (2D) layered structure. In this review, we provide an insightful and concise summary of the intrinsic properties of Sr₂TiO₄, focusing on the electronic, optical, and structural characteristics that render it a promising candidate for photocatalytic applications. Moreover, we delve into the innovative strategies that have been developed to optimize the structural attributes of Sr₂TiO₄. These strategies aim to maximize light absorption, improve charge separation, and accelerate the photocatalytic reaction rates. By highlighting these unique approaches, we strive to contribute to a more profound understanding of the material’s potential and stimulate further advancements in developing Sr₂TiO₄-based photocatalytic systems. The review not only synthesizes the existing knowledge but also offers a perspective in future directions for research and application. As the field of photocatalysis continues to evolve, Sr₂TiO₄ stands poised to play a pivotal role in the quest for more efficient and sustainable solar energy conversion technology.

Photocatalysis is the most promising green approach to solve antibiotic pollution in water, but the actual treatment effect is limited by photocatalytic activity. Herein, Bi and BiOCl were loaded onto the surface of Ce-MOF (metal–organic framework) using an electrostatic adsorption method, and a special ternary heterojunction of Ce/Bi/BiOCl was successfully prepared as a photocatalyst for the degradation of tetracycline (TC). FTIR demonstrated that the obtained photocatalyst contains functional groups such as -COOH belonging to Ce-MOF and characteristic crystal planes of Bi and BiOCl, indicating the successful construction of a ternary photocatalyst. The results of UV–vis absorption spectra confirm that the band gap of Ce/Bi/BiOCl heterojunction is reduced from 3.35 eV to 2.7 eV, resulting in an enhanced light absorption capability in the visible light region. The special ternary heterojunction constructed by Ce-MOF, Bi, and BiOCl could achieve a narrow band gap and reasonable band structure, thereby enhancing the separation of photogenerated charges. Consequently, the photocatalytic performance of the Ce/Bi/BiOCl ternary heterojunction was significantly enhanced compared to Ce-MOF, Bi, and BiOCl. Therefore, Ce/Bi/BiOCl can achieve a photocatalytic degradation rate of 97.7% within 20 min, which is much better than Bi (14.8%) and BiOCl (67.9%). This work successfully constructed MOF-based ternary photocatalysts and revealed the relationship between ternary heterojunctions and photocatalytic activity. This provides inspiration for constructing other heterogeneous catalysts for use in the field of photocatalysis.

Mn/Fe co-doping modulates the electronic structure of transition metal phosphides (Mn–Fe–Ni₂P) to form electronic coupling, which enhances the performance and stability of electrocatalytic overall water splitting.