Layer-Contacted Graphene-Like BN/Ultrathin Bi_(3)O_(4)Br Stacking for Boosting Photocatalytic Molecular Oxygen Activation

Novel graphene-like boron nitride(BN)/Bi_(3)O_(4)Br photocatalysts have been controllably synthesized through a facile solvothermal method for the first time. Layer contact stacking between graphene-like BN and ultrathin Bi_(3)O_(4)Br was achieved with strong interaction. Dehalogenation is designed to harvest more visible light, and the ultrathin structure of Bi_(3)O_(4)Br is designed to accelerate charge transfer from inside to the surface. After graphene-like BN was engineered, photocatalytic performance greatly improved under visible light irradiation. Graphene-like BN can act as a surface electron-withdrawing center and adsorption center, facilitating molecular oxygen activation. O_(2)^(·-)was determined to be the main active species during the degradation process through analyses of electron spin resonance and XPS valence band spectra.

复合治理:地方脱贫进路的一个理论解释——基于153个脱贫摘帽县的扎根研究

准确诠释精准脱贫战略实践以来的地方治理经验是一项亟待推进的研究议题。论文以153个脱贫摘帽县作为分析样本,基于扎根方法提炼“复合治理”分析性概念诠释地方脱贫经验。“复合”属性表明地方减贫过程受到多重机制共同作用而形塑出复杂叠加的治理样态,具体表现为:(1)中央政府建构“刚性时间约束”要件,为地方政府“复合治理”提供外在驱动力;(2)贫困县党委、政府调用“党政统合”形式凸显任务首位、塑造体制联动效应,它是“复合治理”的组织轴心;(3)“复合治理”实践运作依托于横向维度“利益整合”与纵向维度“政治关联”,前者表征政府与市场主体建构治理共识以形成长效治理机制,后者表征地方政府将外生性政治权威嵌入村庄场域提升治理合力。“复合治理”为精准脱贫实践提供了一个理论视角,后续研究应强化对2020年后相对贫困治理实践的实证解读。

Non-radical activation of persulfate with Bi_(2)O_(3)/BiO_(1.3)I_(0.4)for efficient degradation of propranolol under visible light

Non-radical activation of persulfate(PS)by photocatalysts is an effective approach for removing organic pollutants from aqueous environments.In this study,a novel Bi_(2)O_(3)/BiO_(1.3)I_(0.4)heterojunction was synthesized using a facile solvothermal approach and used for the first time for non-radical activation of PS to degrade propranolol(PRO)in the presence of visible light.The findings found that the degradation rate of PRO in the Bi_(2)O_(3)/BiO_(1.3)I_(0.4)/PS system was significantly increased from 19%to more than 90%within 90 min compared to the Bi_(2)O_(3)/BiO_(1.3)I_(0.4)system.This indicated that the composite system exerted an excellent synergistic effect between the photocatalyst and the persulfate-based oxygenation.Quenching tests and electron paramagnetic resonance demonstrated that the non-radical pathway with singlet oxygen as the active species played a major role in the photocatalytic process.The existence of photo-generated holes during the reaction could also be directly involved in the oxidation of pollutants.Meanwhile,a possible PRO degradation pathway was also proposed.Furthermore,the impacts of pH,humic acid and common anions on the PRO degradation by the Bi_(2)O_(3)/BiO_(1.3)I_(0.4)/PS were explored,and the system’s stability and reusability were also studied.This study exhibits a highly productive catalyst for PS activation via a non-radical pathway and provides a new idea for the degradation of PRO.

Enhanced photocatalytic performance of carbon quantum dots/Bi OBr composite and mechanism investigation

Novel carbon quantum dots（CQDs）/Bi OBr composite photocatalysts have been constructed through a facile hydrothermal synthesis in the presence of ionic liquid 1-hexadecyl-3-methylimidazolium bromide（[C16 mim]Br）. Series of characterizations have been performed to confirm the uniform distribution of CQDs in Bi OBr nanosheets and the synergistic effect for photocatalytic degradation organic pollutants between CQDs and Bi OBr. The results show that 3.1 wt% CQDs/Bi OBr photocatalyst possesses the best photocatalytic activity for the degradation of colorless antibiotic tetracycline（TC）, endocrine disrupter bisphenol A（BPA） and dye rhodamine B（Rh B）, under visible light irradiation, which exhibited the highest photocatalytic performance. The enhanced photocatalytic performance for CQDs/Bi OBr composites could be attributed to the wider optical absorption range and fast separation of photogenerated charge carriers after the introduction of CQDs. The key roles of CQDs for the enhanced photocatalytic activity of Bi OBr have been discussed. A possible mechanism of CQDs/Bi OBr on the enhancement of visible light performance was proposed.

Recent Progress in Fiber Optofluidic Lasing and Sensing

Fiber optofluidic laser(FOFL)integrates optical fiber microcavity and microfluidic channel and provides many unique advantages for sensing applications.FOFLs not only inherit the advantages of lasers such as high sensitivity,high signal-to-noise ratio,and narrow linewidth,but also hold the unique features of optical fiber,including ease of integration,high repeatability,and low cost.With the development of new fiber structures and fabrication technologies,FOFLs become an important branch of optical fiber sensors,especially for application in biochemical detection.In this paper,the recent progress on FOFL is reviewed.We focuse mainly on the optical fiber resonators,gain medium,and the emerging sen sing applicatio ns.The prospects for FOFL are also discussed.We believe that the FOFL sensor provides a promising technology for biomedical analysis and environmental monitoring.