Chunhu Li

近年来，二维材料因其在极限薄的厚度下表现的优异物理化学性质而被广泛关注. NaYbSe2因其作为量子自旋液体候选材料和在高压下表现出超导特性而成为研究热点. 然而，目前仍没有系统制备二维NaYbSe2的相关报道. 本研究以重稀土元素金属加氯化钠可控硒化为技术路线，通过化学气相沉积法，以NaCl、Yb和Se作为前驱体，使用氢气与氩气作为载气，成功在R面蓝宝石衬底上制备出了二维NaYbSe2材料. 通过调控生长参数可以制备15 nm至89 nm不同厚度的纳米片，进一步表征结果证实NaYbSe2纳米片具有良好的单晶特性. 此制备方法可以进一步拓展至NaLuSe2、KYbSe2和KLuSe2一系列二维单晶薄片的合成，因此，NaYbSe2等二维材料的可控制备与表现出的优异单晶特性，将推动此类碱金属稀土硒化物材料的物性研究与其在自旋器件领域的应用.

A simple oxidation strategy to synthesize hydroxyl (–OH) and carboxyl (–COOH) co-modified carbon nanotubes (CNTs) for the 2e ⁻ ORR was developed, and they exhibit excellent H ₂ O ₂ electrosynthesis performance in alkaline media.

Photocatalytic H₂O₂ production with H₂O and O₂ as resources is a promising technique. Herein, a g-C₃N₄@CdS (CN@CdS) Z-scheme heterojunction is prepared for photocatalytic H₂O₂ production with a rate of 167.5 μmol/h, which is 5.43 and 5.15 times higher than that of pure g-C₃N₄ and pure CdS. Photoelectronic characterization results reveal the existence of a strong built-in electric field between CdS and g-C₃N₄, which significantly facilitates the separation of photogenerated carriers and preserves the strong redox capacity. Density functional theory (DFT) calculations show that CN@CdS displays lower O₂ adsorption energy and the H₂O₂ is more readily formed. This work provides a novel strategy for the design of photocatalysts with excellent H₂O₂ evolution efficiency.

Under mild conditions, selective conversion of methane to C1 chemicals, such as HCHO, CH₃OH, etc, is a very attractive CH₄ conversion pathway. At present, in order to improve the yield of liquid oxygenates, most methane oxidation is carried out under pressurized conditions, which results in a large number of products without obvious selectivity. To overcome this shortcoming, this study was carried out at room temperature and pressure without any oxidant. By adjusting the crystal facet of anatase TiO₂, the TiO₂-001 nanosheets were prepared by hydrothermal method, and the single liquid oxygenate HCHO 767 μmol/(g·h) with selectivity of 83.3% and C1 liquid oxygenate (HCHO+CH₃OH) with selectivity of 100%. Various characterization methods (TEM, XRD, XPS, EPR) confirmed that the exposure of the crystal facet of TiO₂-001 and the high surface hydroxyl group (Ti-OH) could promote the generation of ·OH, optimize the reaction path, and promote the highly selective generation of HCHO. This work is of great significance for controlling free radical species and generating single liquid oxygenates with high selectivity.

Biomass platform compound 5-Hydroxymethylfurfural (HMF), with its low price and abundant source, can be used as a renewable resource to replace traditional petrochemicals. MOF-808(Zr) has tunable active sites and excellent stability under high temperatures and acidic as well as basic environments, and the unsaturated coordination of metal ions within its framework structure can exhibit Lewis acidity, facilitating catalytic transfer hydrogenation from HMF to 2, 5-Furandimethanol (BHMF). The hydrothermal–impregnation–reduction method was used to prepare Cu/MOF-808 catalysts with high catalytic performance. Formic acid was chosen as the hydrogen donor solvent. The selectivity and yield of BHMF were 75.65% and 71%, respectively, at 150 °C for 4 h. A reaction pathway for the catalytic hydrogen transfer of HMF to BHMF was proposed. The high activity and stability of the Cu/MOF-808 catalyst with dual active sites provide a viable method for feasible hydrogenation of HMF to high value-added compounds.