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Self-cleaning decorative panels rely on the presence of photocatalytic nano-TiO2(NT) to effectively degrade pollutants and achieve a stable decoration effect. However, the method of directly mixing NT with raw materials is limited by its high NT dosage and poor utilization. This study proposes a novel NT composite decorative panel prepared by the multilayer method, which is suitable for architectural decoration and reduces the NT content to achieve stable self-cleaning performance. The study investigates the effects of the NT content, NT particle size, and thickness of the NT-surface layer on the mechanical properties and photocatalytic performance of the panels. The results reveal that an appropriate amount of NT can fill the pores in the cement stone, improve the microstructure of the hydration system, and enhance the compressive strength of the specimens. The compressive strength of the decorative panels that are produced using the multilayer method decreases when the NT-surface layer thickens. The optimal thickness of the NT-surface layer is determined to be 1/7 of the thickness of the panels. Additionally, the optimal NT particle size and NT content in the NT-surface layer are 25 nm and 5%, respectively. Upon exposure to UV lamp irradiation, the decorative panels exhibit a degradation rate of 94% for nitric oxide (NO) and 88% for rhodamine B (RhB). The NO degradation rate of the decorative panels initially increases and subsequently decreases with the increase in moisture content, and the optimal moisture content is approximately 1.2%. Insufficient or excessive water can reduce the photocatalytic efficiency of the decorative panels. When the NO concentration increases, the degradation rate of the decorative panels decreases, but the total amount of NO degradation increases. After 6 months of exposure to outdoor conditions, the NO degradation rate of the decorative panels decreased by 15% but remained high at 80%.

The utilization of thermal reflective materials on the building surface is one of the most promising methods for energy-saving in tropical and subtropical regions. In this work, nano TiO2(NT) is used to enhance the mechanical properties and thermal reflectance of inorganic decorative panels, which are widely used for building exterior walls in China. The obtained results show that NT can modify the pore size distribution of the decorative panels and reduce the presence of macropores, and the compressive strength of the decorative panels with 2% NT increased by 4.78%. The thermal reflective properties of the decorative panels initially increased and then decreased with increasing NT content and particle size. Notably, the panels made of 6% NT with a particle size of 100 nm exhibited higher thermal reflectivity, resulting in a surface temperature decrease of 3.9 °C compared to the reference sample. Furthermore, compounding different particle sizes NT is employed to produce the decorative panels, and about a 4.5 °C decrease can be observed in this study. Mid- and far-infrared absorption spectroscopy results show that the thermal emissivity is improved in the mid- and far-infrared region of 2.5–25 μm when 100-nm and 25-nm NT were compounded at a weight ratio of 1:1. Additionally, to further evaluate the energy-saving of the decorative panels, the Designer’s Simulation Toolkit (DeST) is employed, which demonstrates that the thermal reflective decorative panels with 6% NT can save 7.19% of building air-conditioning energy consumption and reduce the indoor temperature by 1.5 °C.

In this review, we have summarized the research progress on supported solid superbases and their catalytic applications. Four types of solid superbases supported on different materials including single metal oxides, composite metal oxides, molecular sieves and other materials as well as their respective catalytic applications are further discussed by taking several examples, thus giving a good inspiration for the study and development of supported solid superbase catalysts in the future.

Background: The design of a highly active catalyst is a key point in olefins epoxidation. Recently, polyoxometalates have received an increasing interest in selective oxidation of organic compounds. Their scope as nanoparticle carriers is of immense importance as the high anionic charge associated with them prevents sintering of the nanoparticles which is a major issue related to nanoparticle based catalysts thus increasing the stability of the catalyst. Objective: We have immobilized Na9PMo11O39 (PMo11) and gold nanoparticles on chloropropyltriethoxysilane functionalized SBA-15 mesoporous material. We investigated the molecular oxygen activation ability and stability of this heterogeneous hybrid catalytic system for green epoxidation of cyclohexene under mild reaction conditions. Method: PMo11 was prepared according to the literature, while PMo11/CPTES-SBA-15, Au/CPTES-SBA-15 and Au/PMo11/CPTES-SBA-15 were prepared by wet deposition method. The catalytic performance was evaluated in a PTFE lined autoclave and analysis was done by gas chromatography. Results: Cyclohexene epoxidation was carried out on different heterogeneous catalytic systems which included polyoxometalate and CPTES-SBA-15 support, nano gold and CPTES-SBA-15 support and the hybrid material Au/PMo11/CPTES-SBA-15 with varying amounts of doped nanogold. All the samples showed good conversion of cyclohexene and significant selectivity for oxidized products with molecular oxygen as an oxidant under mild conditions. 1 % Au/PMo11/CPTES-SBA-15 delivered 48.1 % conversion and 35.9 % selectivity to epoxide. Conclusion: The CPTES-SBA-15 supported Au/PMo11 hybrid catalytic system demonstrated relatively high catalytic activity and selectivity for the green epoxidation of cyclohexene with molecular oxygen as an oxidant under mild reaction conditions. The hybrid catalyst was regenerated and reused for three cycles without compromising the catalytic performance.

Selective oxidation of olefins using molecular oxygen is a great challenge. This study reports two types of novel eco-friendly heterogeneous hybrid catalysts. One comprises of a lacunary Keggin-type polyoxometalate (POM) GaW11linked to nano-sized silica using (3-aminopropyl) triethoxysilane (APTES) to form GaW11-APTES@SiO2. Another catalyst is Au/GaW11-APTES@SiO2prepared by wet deposition of nano-gold on the former one. The catalysts were characterized and used for the solvent-free oxidation of cyclohexene with molecular oxygen under mild reaction conditions. Both the catalysts showed good conversion and significant selectivity towards oxidized products for cyclohexene. GaW11-APTES@SiO2showed a high conversion of up to 62.02% with a selectivity of 59.13% towards epoxide at a mild temperature of 50°C. Au/GaW11-APTES@SiO2showed a conversion of 69.32% with 57.34% selectivity to 2-cyclohexene-1-ol at a temperature of 80°C. The heterogeneous catalysts were reused several times with no significant loss in conversion or selectivity towards the oxidized products.

To figure out the different electrochemical performance of ordered and disordered nano-intermetallic catalysts and their mechanisms, we successfully synthesized AuCu/C electrocatalysts through a modified co-precipitation method and obtained their ordered and disordered structure at different temperatures. A systematic comparison between the ordered and disordered AuCu/C with the similar composition, particle size, valence state was conducted. The AuCu/C nanoparticles with better structure-ordering showed superior catalytic performance for the oxygen reduction reaction (ORR) than the disordered ones. It was also observed that the disordered AuCu/C tended to form a Cu-shell structure which was believed to be detrimental to ORR electrocatalysis.

In this paper, the metal oxide supports and active component precursors of SO42−/MxOysolid acid were screened, and S2O82‐−/Cr2O3-Fe2O3(S2-CrFe) was prepared. The NH3-TPD results showed that the solid acids loaded with S2O82−had stronger acidity than those loaded with SO42−, and the mixture of the two metal oxides could adjust the acidity of the solid acids. The optimum conditions for the preparation of S2-CrFe were as follows: the mass ratio of Cr2O3to Fe2O3was 1:1, the concentration of ammonium persulfate solution was 1 mol/L, and the calcination temperature was 550 °C. The yield of esterification catalyzed by the solid acid obtained under these conditions was 91.2%. The stability of the new solid acid was investigated, and it was found that S2-CrFe was easy to be deactivated, so it was considered to be modified by organosilane and lanthanum oxide. The experimental results showed that after the modified solid acid was recycled for four times, the yield of ethyl acetate was more than 60%.

To figure out the different electrochemical performance of ordered and disordered nano-intermetallic catalysts and their mechanisms, we successfully synthesized AuCu/C electrocatalysts through a modified co-precipitation method and obtained their ordered and disordered structure at different temperatures. A systematic comparison between the ordered and disordered AuCu/C with the similar composition, particle size, valence state was conducted. The AuCu/C nanoparticles with better structure-ordering showed superior catalytic performance for the oxygen reduction reaction (ORR) than the disordered ones. It was also observed that the disordered AuCu/C tended to form a Cu-shell structure which was believed to be detrimental to ORR electrocatalysis.