Position-selected cocatalyst modification on a Z-scheme Cd_(0.5)Zn_(0.5)S/NiTiO_(3) photocatalyst for boosted H_(2) evolution

Photocatalytic water splitting by semiconductors is a promising technology to produce clean H_(2) fuel,but the efficiency is restrained seriously by the high overpotential of the H_(2)-evolution reaction together with the high recombination rate of photoinduced charges.To enhance H_(2) production,it is highly desirable yet challenging to explore an efficient reductive cocatalyst and place it precisely on the right sites of the photocatalyst surface to work the proton reduction reaction exclusively.Herein,the metalloid NixP cocatalyst is exactly positioned on the Z-scheme Cd_(0.5)Zn_(0.5)S/NiTiO_(3)(CZS/NTO)heterostructure through a facile photodeposition strategy,which renders the cocatalyst form solely at the electron-collecting locations.It is revealed that the directional transfer of photoexcited electrons from Cd_(0.5)Zn_(0.5)S to Ni_(x)P suppresses the quenching of charge carriers.Under visible light,the CZS/NTO hybrid loaded with the Ni_(x)P cocatalyst exhibits an optimal H_(2) yield rate of 1103μmol h^(-1)(i.e.,27.57 mmol h^(-1)g^(-1)),which is about twofold of pristine CZS/NTO and comparable to the counterpart deposited with the Pt cocatalyst.Besides,the high apparent quantum yield(AQY)of 56%is reached at 400 nm.Further,the mechanisms of the cocatalyst formation and the H2 generation reaction are discussed in detail.

Defect and nanostructure engineering of polymeric carbon nitride for visible-light-driven CO_(2) reduction

Sunlight-induced photocatalytic carbon dioxide(CO_(2))reduction to energy-rich chemicals by metal-free polymeric carbon nitride(CN)semiconductor is a promising tactic for sustained solar fuel production.However,the reaction efficiency of CO_(2)photoreduction is restrained seriously by the rapid recombination of photogenerated carriers on CN polymer.Herein,we incorporate 2-aminopyridine molecule with strong electron-withdrawing group into the skeleton edge of CN layers through a facile one-pot thermal polymerization strategy using urea as the precursor,which renders a modified carbon nitride(ACN)with extended optical harvesting,abundant nitrogen defects and ultrathin nanosheet structure.Consequently,the ACN photocatalyst with desirable structural features attains enhanced separation and migration of photoexcited charge carriers.Under visible light irradiation with Co(bpy)^(2+)_(3)as a cocatalyst,the optimized ACN sample manifests a high CO_(2)deoxygnative reduction activity and high sta-bility,providing a CO yielding rate of 17μmol h^(-1),which is significantly higher than that of pristine CN.The key intermediates engaged in CO_(2)photoreduction reaction are determined by the in situ diffuse reflectance infrared Fourier transform spectroscopy,which sponsors the construction of the possible photocatalytic CO_(2)reduction mechanism on ACN nanosheets.

2型糖尿病患者颈动脉内膜中层厚度与血清无翅型MMTV整合位点家族成员5a及相关因素的关系

目的探讨2型糖尿病(T2DM)患者颈动脉内膜中层厚度(CIMT)与血清无翅型MMTV整合位点家族成员5a(Wnt5a)及相关因素的关系。方法选取2020年9月至2021年12月于河南省人民医院内分泌科住院的T2DM患者为研究对象。检测其血清Wnt5a、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)及转化生长因子(TGF)-β1水平,测定其CIMT。依据CIMT将患者分为无增厚组(CIMT<1.0 mm)、增厚组(1.0 mm≤CIMT<1.5 mm)和斑块组(CIMT≥1.5 mm)3组。采用单因素方差分析、Kruskal-Wallis H检验或χ2检验对患者的一般临床资料进行组间比较;采用Spearman相关分析法对CIMT与Wnt5a、IL-6、TNF-α、TGF-β1,以及血清Wnt5a与IL-6、TNF-α、TGF-β1的相关性进行分析;采用多重线性回归分析法分析患者CIMT、血清Wnt5a的影响因素。结果共纳入163例患者。其中,无增厚组60例,增厚组48例,斑块组55例。与无增厚组和增厚组相比,斑块组的CIMT、Wnt5a、IL-6、TNF-α、TGF-β1均更高(均P<0.001)。相关性分析结果显示,CTMI与Wnt5a(r=0.717)、IL-6(r=0.544)、TNF-α(r=0.524)、TGF-β1(r=0.803)均呈正相关(均P<0.001),血清Wnt5a与IL-6(r=0.465)、TNF-α(r=0.453)、TGF-β1(r=0.631)均呈正相关(均P<0.001)。多重线性回归分析结果显示,Wnt5a、IL-6、TGF-β1均是CIMT的影响因素(均P<0.05),IL-6、TGF-β1均是血清Wnt5a的影响因素(均P<0.05)。结论T2DM患者的CIMT与Wnt5a及IL-6、TGF-β1等密切相关。