High performance hydroxyapatite (HA) ceramics with excellent densification and mechanical properties were successfully fabricated by digital light processing (DLP) three-dimensional (3D) printing technology. It was found that the sintering atmosphere of wet CO₂ can dramatically improve the densification process and thus lead to better mechanical properties. HA ceramics with a relative density of 97.12% and a three-point bending strength of 92.4 MPa can be achieved at a sintering temperature of 1300 , which makes a solid foundation for application ℃ in bone engineering. Furthermore, a relatively high compressive strength of 4.09 MPa can be also achieved for a DLP-printed p-cell triply periodic minimum surface (TPMS) structure with a porosity of 74%, which meets the requirement of cancellous bone substitutes. A further cell proliferation test demonstrated that the sintering atmosphere of wet CO₂ led to improve cell vitality after 7 days of cell culture Moreover, with the possible benefit from the bio-inspired structure, the 3D-printed TPMS structure significantly improved the cell vitality, which is crucial for early osteogenesis and osteointegration.

Photothermal coupling catalysis technology has been widely studied in recent years and may be a promising method for CO₂ reduction. Photothermal coupling catalysis can improve chemical reaction rates and realize the controllability of reaction pathways and products, even in a relatively moderate reaction condition. It has inestimable value in the current energy and global environmental crisis. This review describes the application of photothermal catalysis in CO₂ reduction from different aspects. Firstly, the definition and advantages of photothermal catalysis are briefly described. Then, different photothermal catalytic reductions of CO₂ products and catalysts are introduced. Finally, several strategies to improve the activity of photothermal catalytic reduction of CO₂ are described and we present our views on the future development and challenges of photothermal coupling. Ultimately, the purpose of this review is to bring more researchers’ attention to this promising technology and promote this technology in solar fuels and chemicals production, to realize the value of the technology and provide a better path for its development.

Due to the lack of commercially available high-quality hydroxyapatite (HA) powder, it is still rarely reported by the literature concerning the development of UV resin for digital light processing 3D printing. The previous studies still had the problem of delamination and also poor sintering performance led by low solid-load slurry. Here low viscosity and high solid-load hydroxyapatite (HA) UV resin suspensions were developed for digital light processing 3D printing. In this study, the effect of the type of dispersant, the dose levels of dispersant and the solid load of HA powder on the rheology properties were thoroughly investigated to obtain a flowable highly-concentrated HA UV resin suspension. Finally, a 40vol% slurry with viscosity of 3.7Pa·s at a shear rate of 10 s-1 was successfully developed. After 3D printing and sintering, a dense ceramic with relative density of 95.85% can be obtained at a sintering temperature of 1300°C.

Three-dimensional ordered macroporous NiFe₂O₄ (3DOM-NFO) powder was synthesized through the direct templating method combined with the sol–gel combustion technique. Polymethyl methacrylate (PMMA) spheres with different sizes were used as the hard templates. In order to understand the effect of PMMA spheres mean size on the structure and catalytic activity of synthesized 3DOM-NFO, the detailed characterization of the material was carried out by XRD, SEM, BET, XPS, UV–VIS, and DRS techniques. Direct hydrogeneration production of CH₄ from CO₂ and H₂O was used to evaluate the catalysis performance of 3DOM-NFOs. The production of CH₄ evolution can reach 1040.8 μmol/g at 350 °C and ambient pressure when 300 nm template was used. It was concluded that the specific surface area and moderate concentration of oxygen vacancies are the crucial factors affecting the catalysis properties. Reasonably high turnover number of 0.244 and high CH₄ conversion efficiency of 0.897% were obtained in this study. 3DOM-NFO can be a promising catalyst for hydrocarbon fuel production by directly using CO₂ and H₂O as the safe and cheap feedstocks. CH₄ evolution over time for different 3DOM-NFO catalysts at 350 °C.

To gain insight into photocatalytic behavior, transient absorption spectroscopy (TAS) was used to study LaCo_xMn_1−xO₃, LaMn_xNi_1−xO₃ and LaNi_xCo_1−xO₃ (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) on a microsecond time scale. The results show that the electron lifetime is key to determining the photocatalytic reduction of CO₂. This is the first time that the photogenerated electron lifetime in perovskite has been proposed to express the performance of the photocatalytic reduction of CO₂ with H₂O into CH₄. In all cases, the decay curve can be well explained by two consecutive first-order kinetics, indicating that the electron exists within two major populations: one with a short lifetime and the other one with a long lifetime. The long-lived electrons are the rate-limiting species for the photocatalytic reaction and are related to the activity of the photocatalytic reduction of CO₂ with H₂O to produce CH₄. For different photocatalysts, we find that the longer the electron decay lifetime is, the stronger the electron de-trapping ability is, and the electrons perform more activity. In this paper, TAS can not only detect the micro-dynamics process of carriers, but it is also demonstrated to be an easy and effective method for screening the most active catalyst in various catalysts for the photocatalytic reduction of CO₂ with H₂O accurately and quickly.