Dongliang Zhang

Steering CO₂ photoreduction toward C₂ hydrocarbons remains challenging because of the sluggish multielectron/proton-transfer kinetics and the high energetic demand for C-C coupling. Herein, we report a flame-spray-pyrolysis strategy to construct Au-CeO_x nanostructures featuring coexisting symmetric oxygen vacancies (Ce-O_v-Ce) and symmetry-broken oxygen vacancy (Au-O_v-Ce) motifs at the Au-CeO_x interface. The symmetric Ce-O_v-Ce sites provide favorable adsorption environments for CO₂ activation, whereas the symmetry-broken Au-O_v-Ce sites induce interfacial electron redistribution and promote electron enrichment. The cooperative interaction between these two vacancy configurations shifts the reaction route from *CO desorption toward deep hydrogenation and *CH₃-mediated C-C coupling. As a result, the optimized Au-CeO_x-SAO_v catalyst achieves a C₂H₆ production rate of 2581 μmol g_Au^-1 h^-1 with a selectivity of 88.14% and an electron utilization rate of 41.22 mmol g_Au^-1 h^-1 in photocatalytic CO₂ reduction with H₂O. Mechanistic studies suggest that the symmetry-broken Au-O_v-Ce sites stabilize hydrogenated C₁ intermediates and lower the energetic requirement for coupling two *CH₃ species. This work establishes symmetry-differentiated oxygen-vacancy engineering as an effective strategy for directing multielectron CO₂ photoreduction toward C₂ hydrocarbons.

Herein, a molecularly imprinted TiO₂ photocatalyst (T@MIP) was designed for the targeted degradation of tetracycline by combining flame spray pyrolysis with surface molecular imprinting technology. The FSP-derived TiO₂ substrate, rich in surface defects and hydroxyl groups, serves as a key anchor for the subsequent prepolymerization of specific molecularly imprinted sites. The T@MIP catalyst exhibits excellent overall performance, including high selectivity for TC in a multipollutant system, exceptional degradation efficiency, and near-complete mineralization. Notably, mechanistic studies using free-radical EPR and in situ DRIFTS revealed that the molecularly imprinted sites simultaneously enrich TC molecules, leading to synergistic degradation dominated by ·O₂^- and h⁺. This work establishes a new model for the development of "smart" photocatalytic systems for precision environmental remediation.

CeO₂ polishing powder is extensively used in chemical mechanical polishing (CMP) applications on Si substrate materials. This study synthesized sub-micrometer, spherical, fluoride-free, and fluorine-doped CeO₂ particles using the precipitation method at various calcination temperatures. Key parameters of the CeO₂ particles, such as particle size, morphology, crystallinity, and Ce³⁺ content, were obtained using a laser particle size analyzer (LPSA), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). In conjunction with CMP experiments on K9 optical glass, the service life and polishing performance were evaluated. It was determined that crystallinity is the most critical factor, with a particularly pronounced role of the (111) crystal plane. Fluorine can enhance crystallinity and promote grain growth; hence, fluorine doping can improve the crystallinity of the powder at relatively low calcination temperatures (600 °C), reducing energy consumption. Additionally, appropriate particle size, rough surface morphology, and hydrophilicity of particles can also contribute to the enhancement of material removal rate (MRR). Fourier transform infrared spectroscopy (FT-IR) confirmed that Ce-O-Si bonding during the CMP process facilitated the disintegration of the glass. XPS verified that some Ce⁴⁺ can be reduced to Ce³⁺ during the CMP process, and the presence of Ce³⁺ can strengthen Ce-O-Si bonding. Ultimately, the glass is primarily removed in a lumped Q³ (Si₂O₅^2- sheet) form through the formation of Ce-O-Si bonds at the CeO₂-glass interface. This study further refines the polishing mechanism of CeO₂ with glass during the CMP process, succinctly summarized in the TOC graphic.

Bacillus anthracis has gained international attention as a deadly bacterium and a potentially deadly biological warfare agent. Dipicolinic acid (DPA) is the main component of the protective layer of anthracis spores, and is also an anthrax biomarker. Therefore, it is of great significance to explore an efficient and sensitive DPA detection method. Herein, a novel ratio hybrid probe (CQDs-PIL-Eu³⁺) was prepared by a simple one-step hydrothermal method using carbon quantum dots (CQDs) as an internal reference fluorescence and a covalent bond between CQDs and Eu³⁺ by using a polyionic liquid (PIL) as a bridge molecule. The ratiometric fluorescence probe was found to have the characteristics of sensitive fluorescence visual sensing in detecting DPA. The structure and the sensing properties of CQDs-PIL-Eu³⁺ were investigated in detail. In particular, the fluorescence intensity ratio of Eu³⁺ to CQDs (I₆₁₆/I₄₄₀) was linear with the concentration of DPA in the range of 0–50 μM, so the detection limit of the probe was as low as 32 nm, which was far lower than the DPA dose released by the number of anthrax spores in human body (60 μM) and, thus, can achieve sensitive detection. Therefore, the ratiometric fluorescence probe in this work has the characteristics of strong anti-interference, visual sensing, and high sensitivity, which provides a very promising scheme for the realization of anthrax biomarker DPA detection.

Phosphoric acid-based porous geopolymers were prepared by two different foaming agents (H₂O₂ and Al powder) with phosphoric acid as the activator. High-magnesium nickel slag (HMNS) and fly ash (FA) were the precursor combination. The effects of foaming agent types and contents on the properties of HMNS-FA-phosphate-based porous geopolymers were investigated in terms of dry density, pore structure, compressive strength, thermal conductivity, and water absorption. The phase was analyzed by x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). It was found that both foaming agents could successfully prepare porous geopolymers, and the compressive strength and dry density of porous geopolymers gradually decreased and the low-thermal conductivity and water absorption gradually increased with the increase in foaming agent content. The foaming agents formed porous structures inside porous geopolymers but did not affect the phases of geopolymerization reactions. This study demonstrates that both foaming agents can be used to prepare HMNS-FA-phosphate-based porous geopolymers for the application of phosphate-activated geopolymers in the direction of refractory materials.