Photocatalytic reduction of CO₂ into valuable solar fuels represents a promising strategy to address both energy crises and carbon emissions. Bismuth-based semiconductors have emerged as attractive visible-light-driven photocatalysts due to their suitable band structures, layered architectures, and tunable morphologies. This review systematically summarizes recent advances in Bi-based photocatalysts for CO₂ photoreduction. First, the fundamental principles and key challenges of CO₂ photoreduction are outlined. Subsequently, the structural and electronic characteristics of typical Bi-based materials, including Bi₂O₃, Bi₂S₃, Bi₂MO₆ (M = W; Mo), BiVO₄, and BiOX (X = Cl; Br; I), are discussed. Emphasis is placed on design strategies to enhance photocatalytic performance, such as vacancy engineering, microstructure control, crystal facet engineering, heterojunction construction, cocatalyst loading, and their combinations. A comprehensive comparison of catalytic activities under various conditions is also provided. Finally, current limitations and future perspectives are highlighted, aiming to guide the rational design of efficient and stable Bi-based photocatalysts for CO₂ conversion.

Mg–Y–Zn alloys have attracted considerable attention for lightweight structural applications; however, the influence of extrusion temperature on microstructural evolution and the underlying mechanisms governing strength–ductility synergy remains insufficiently understood. In this study, a novel YZG921 (Mg–9Y–1.8Zn–1.2Gd–0.5Zr–0.3Ca, wt.%) alloy was fabricated by hot extrusion at temperatures ranging from 480 to 520 °C. The microstructure, mechanical properties, and deformation behavior were systematically investigated using SEM, TEM, EBSD, in situ EBSD, and slip-trace analysis. The results show that extrusion temperature significantly affects the evolution of secondary phases, grain size, and texture intensity. At 500 °C, an 18R-LPSO phase was formed, accompanied by a more homogeneous distribution of secondary phases and the finest grain structure (~3.8 μm), whereas the average grain size remained close to 10 μm for the alloys extruded at 480 °C and 520 °C. Meanwhile, the maximum basal texture intensity decreased from 4.16 to 4.79 m.r.d. to 2.18–2.58 m.r.d. Mechanical testing revealed that the alloy extruded at 500 °C exhibited the optimum strength–ductility balance, with an ultimate tensile strength of 498.4 MPa and an elongation of 13.8%. In situ EBSD analysis showed that the fraction of low-angle grain boundaries increased from ~7% to 43% during tensile deformation, while the average KAM value increased from ~0.5° to 0.88°. Slip-trace analysis further demonstrated that plastic deformation was predominantly governed by basal slip, accounting for approximately 84.2% of the activated slip systems. The superior mechanical performance achieved at 500 °C is attributed to the synergistic effects of grain refinement, LPSO and second-phase strengthening, texture weakening, and sustained strain hardening. These findings provide insights into microstructure–property relationships and offer guidance for the optimization of thermomechanical processing parameters in Mg–Y–Zn alloys.

In this study, the synergistic influence of Er alloying and heat treatment on the as-cast Mg-5Sm-0.2Ni alloy were comprehensively investigated. The results show that Er addition promotes the formation of a Mg(Er,Sm)₃ phase during the solidification process, and subsequent heat treatment alters the morphology, distribution and volume fraction of the Ni-containing LPSO phases, meanwhile promoting the precipitation of noodle-like Mg3Sm phases from an α-Mg matrix. Compared to the as-cast Mg-5Sm-0.2Ni alloy, the yield strength of the Mg-5Sm-1Er-0.2Ni alloy subjected to heat treatment increased from 88 ± 4 MPa to 144 ± 5 MPa, and the corrosion rate decreased from 492.6 ± 14.2 mm/year to 166.2 ± 12.4 mm/year. The enhanced yield strength of the heat-treated Mg-5Sm-1Er-0.2Ni alloy mainly originates from the finely dispersed Mg(Er,Sm)₃ phases and the noodle-like Mg₃Sm precipitates, while the reduced corrosion rate is due to the decreased volume fraction and coarsened size of the LPSO phases, which weaken the galvanic corrosion effect. This study provides a new approach for the preparation of Mg-Sm-Er-Ni alloys with high yield strengths and controlled corrosion rates.

With the development of science and technology, heat dissipation has become a bottleneck problem restricting the development of fields such as transportation, machinery, electronics, and aerospace. Aiming to resolve the bottleneck problem of low thermal conductivity in traditional commercial magnesium alloys, this paper designed alloy compositions to investigate the effects of the solid solubility of La and Ce, and the size, morphology, distribution, and volume fraction of the second phase in the microstructure of magnesium alloys during the heat dissipation performance of the Mg-RE binary system and the Mg-Mn-La(Ce) system. The research shows that through CAFE simulation calculations, regulation can be achieved via the following methods: increasing the average nucleation undercooling, which leads to larger grain sizes; reducing the nucleation density, which results in larger grain sizes; and increasing the standard deviation of the average nucleation undercooling, which reduces the area of small grains while increasing the area of large grains. The thermal conductivity of both as-cast and solid-solution Mg-La (Ce) binary alloys gradually decreases with the increase in the added elements. However, after solution treatment, the thermal conductivity of the Mg-La (Ce) binary alloys is higher than that of the as-cast alloys. The addition of the Ce element helps refine the as-cast microstructure of the Mg-0.5Mn alloy. With the increase in Ce addition, the volume fraction of the Mg12Ce phase also increases. The thermal conductivity of the as-cast Mg-0.5Mn-xCe alloy gradually increases with rising temperature. Meanwhile, at room temperature, the thermal conductivity of the as-cast Mg-0.5Mn alloy gradually decreases with the increase in Ce addition, and the rate of decline gradually slows down due to the precipitation of the Mg12Ce phase.