Science China Materials

Oxygen vacancy-rich bismuth oxysulfide (Bi2O2S) with layered structure was prepared for efficient photocatalytic CO2 reduction under visible light irradiation. The existence of rich oxygen vacancies in Bi2O2S, which was proven by sufficient characterization, can provide abundant active sites, improve CO2 adsorption and activation abilities and boost the separation efficiency of photogenerated carriers, as determined by theoretical and experimental analyses. As a result, Bi2O2S with rich oxygen vacancies achieves excellent CO2 conversion with a CH4 production of 65.8 µmol g−1 under 90 min of visible light irradiation, which was 27-fold higher than the pristine Bi2O2S. The mechanism of photocatalytic conversion of CO2 to CH4 was also determined by in situ FT-IR analyses. This study provides an in-depth understanding of the development of Bi-O-S system photocatalysts through defect engineering for photocatalytic CO2 reduction.

Transition metal oxides (TMOs) as low-cost hydrogenation catalysts exhibit high selectivity and durability. However, due to the lack of metal activation sites required for H2 dissociation, the harsh conditions such as high pressure (1–5 MPa H2) and high temperature (100–250°C) are usually needed to achieve H2 activation. Herein, we developed an amorphous nickel oxide nanosheets with an exceptionally low coordination number of the Ni-Ni shell, and this unique feature not only facilitated H2 activation but also preserved remarkable selectivity (∼99%) in the hydrogenation of vinyl group under mild conditions (room temperature (25°C) and low H2 pressure (100 kPa)).

Graphitic carbon nitride (g-C3N4) coupled with NiCoP nanoparticles with sizes around 5 nm have been fabricated via a controllable alcohothermal process. NiCoP is an excellent electron conductor and cocatalyst in photocatalytic reactions. The coupling between tiny NiCoP nanoparticles and g-C3N4 through in-situ fabrication strategy could be a promising way to eliminate the light screening effect, hinder the recombination of photo-induced charge carriers, and improve the charge transfer. The NiCoP/g-C3N4 nanohybrids exhibit an excellent photocatalytic activity in the hydrogen generation, with a significantly improved performance compared with original g-C3N4, CoP/g-C3N4 and Ni2P/g-C3N4, respectively. This study paves a new way to design transition metal phosphides-based photocatalysts for hydrogen production.

近年来, 以耐甲氧西林金黄色葡萄球菌(MRSA)为代表的“超级细菌”不断被发现和扩散, 已经严重威胁人类健康, 因此, 研制新型、 高效的抗菌剂迫在眉睫. 以宿主防御肽及其模拟物为代表的多肽和聚合物近年来得到广泛关注. 而分子刷作为一类独特的聚合物也显示 了很多特殊的性能. 我们结合前期研究, 首次将两种开环聚合体系即β-内酰胺开环聚合和N-羧基环内酸酐(NCA)开环聚合体系相结合, 以 β多肽为骨架结构进而通过其氨基功能基团进一步引发NCA开环聚合, 合成了侧链具有多个聚赖氨酸的α/β杂化多肽聚合物分子刷. 这种 新型分子刷对多种MRSA菌株均展现出高效的抗菌活性, 甚至优于万古霉素. 通过扫描电子显微镜(SEM)表征, 揭示了α/β杂化多肽聚合物 分子刷的抗菌机理与宿主防御肽类似, 是通过破坏细菌细胞膜的完整性杀菌. α/β杂化多肽聚合物分子刷高度可调的结构特点和高效的抗 菌活性, 显示了其在抗菌研究和应用中的潜力.