A review on heterogeneous photocatalysis for environmental remediation:From semiconductors to modification strategies

Heterogeneous photocatalysis,an advanced oxidation process,has garnered extensive attention in the field of environmental remediation because it involves the direct utilization of solar energy for the removal of numerous pollutants.However,the application of heterogeneous photocatalysis in environmental remediation has not achieved the expected consequences due to enormous challenges such as low photocatalytic efficiencies and high costs of heterogeneous photocatalysts in large-scale practical applications.Furthermore,pollutants in the natural environment,including water,air,and solid phases,are diverse and complex.Therefore,extensive efforts should be made to better understand and apply heterogeneous photocatalysis for environmental remediation.Herein,the fundamentals of heterogeneous photocatalysis for environmental remediation are introduced.Then,potential semiconductors and their modification strategies for environmental photocatalysis are systematically presented.Finally,conclusions and prospects are briefly summarized,and the direction for the future development of environmental photocatalysis is explored.This review may provide reference directions toward understanding,researching,and designing photocatalytic remediation systems for various environmental pollutants.

Enhanced photocatalytic performance of MoS_2 modified by AgVO_3 from improved generation of reactive oxygen species

In this work, an efficient AgVO3/MoS 2 composite photocatalyst was successfully synthesized via a hydrothermal method. The photocatalytic activity of the as-prepared photocatalyst was evaluated by using it for assessing the degradation of different organic pollutants under visible-light irradiation. The composite 3%-AgVO3/MoS 2 catalyst demonstrated a significantly enhanced photocatalytic activity compared to the pure compounds（AgVO3 and MoS2）. The reason behind the excellent photocatalytic performance was the modification of MoS 2 by AgVO3 to facilitate O2 adsorption/activation. In addition, the composite catalyst facilitates the two-electron oxygen reduction reaction whereby H2O2 is generated on the surface of MoS 2 to produce additional reactive oxygen species（ROSs）. ESR coupled with the POPHA fluorescence detection method and a free radical capture experiment were used to elucidate the mechanism of formation of the ROSs, including ·OH, ·O2- and H2O2. Furthermore, the generation of additional ROSs could accelerate electron consumption, leaving behind more holes for the oxidation of organic pollutants. A possible photocatalytic mechanism of the composite is also discussed.

材料弹性对摩擦触觉感知的影响研究

材料弹性是影响触觉感知的物理属性之一,从皮肤的“感”和大脑的“知”系统研究材料弹性对触感的影响规律具有重要意义。通过对手指触摸不同弹性特征表面的摩擦、振动信号以及激发的触感脑电信号进行特征参数提取,建立了材料弹性模量E与触感特征参数的关系,实现了弹性表面触感的部分量化表征。结果显示:手指触摸橡胶材料的摩擦力以滞后摩擦分量为主;手指触摸陶瓷和塑料材料时滞后摩擦和黏着摩擦共同影响表面接触摩擦力。相关性分析显示材料E与手指触摸材料的摩擦因数μ、振动频谱最大幅值A_(max)、振动信号的递归参数角线长度均值L和垂直线段长度均值TT均呈负相关,表明材料E越小,振动系统的稳定性越差,复杂度越高。大脑触觉感知的加工时间为触摸开始后的200~400 ms之间,弹性触感激活的脑区主要是大脑中后部的顶叶区及枕叶区;相关性分析显示材料E和触感脑电P300峰值呈正相关,说明材料E越低,激发的大脑神经元兴奋度和注意力越低。手指触摸振动信号A_(max)与触感脑电信号的P300幅值负相关,表明触觉感受体的近端机械刺激与大脑的认知相关联。触摸过程的μ、A_(max)、 L、 TT、和P300峰值与材料E具有明显的关联性,可作为表征材料触摸弹性的特征参数。