Study On Construction Of Micro-electric Field And Property Of Photocatalyst

Converting solar energy into specific chemical energy by photocatalysis is apromising way of addressing the challenge of energy depletion and environment pollution.However,the most daunting problem for obstructing industrial applicationsof photocatalysis is the low activity caused by photo-generated carrier recombinationin photocatalysts.To improve the separation efficiency of photo-generated electronsand holes,numerous measures have been made by researchers,such as loading co-catalysts,doping ions or metals,and optimizing the synthetic methods of catalysts.Although these methods have shown improved effect greatly,high cost and stringent manufacturing operation restrain the applications at the practical level.Consequently,we need to explore a new effortless technology which have refulgent applicationprospect to ameliorate this issue.In this research,the concept of ’micro-electric field’ has been introduced into the field of photocatalysis.With the driving effect of micro-electric field in situ,theseparation of photo-induced carriers has been accelerated,and hence,the photocatalytic performance of samples has been improved.Owing to the inhibited recombination rate of carriers,more electrons migrate to the surface of material toparticipate the photocatalytic reaction,and the tendency is proceed to the directionwhich needs multi-electrons to participate with the improved photocatalytic yields forwhole reaction.Such a novel and convenient technology for energy transformationnot only makes contributions in improving the performance of material but also shows great potential in changing the selectivity of catalytic reaction and collecting mechanical energy vibration in the nature environment.Surrounding with theestablishment and using of ’micro-electric field’,we conduct some works listed below:Synthesizing the ZnO piezoelectric semiconductors with different morphology and investigate the effect of ultrasonic irradiation on the photocatalytic performanceof reducing CO₂.Ultrasonic can elicit the piezoelectric effect of photocatalysts and increase the electron density on the surface of materials,and thus,the selectivity of methane production has been improved.This modified method provides an additional driving force to enhance multi-electron reactions by using the piezoelectric effect.Synthesizing NaNbO₃-CdS hybrid composite simultaneously and the photocatalytic H₂ evolution for the as-synthesized samples has been measured.The spontaneous polarization electric field intrinsically existed in NaNbO₃ can be utilized as a driving force for steering the charge carriers separation of CdS photocatalyst,and consequently,the photocatalytic visible activity of NaNbO₃-CdS composite has been improved.This special conjunction provides new insights in designing and using photocatalysts with superior activity.