Formation of uniform reduced graphene oxide films on modified PET substrates using drop-casting method

In this work,uniform reduced graphene oxide（RGO） films were formed on poly-（ethylene terephthalate）（PET） substrates using a simple drop-casting method.We investigated four types of substrates：unmodified PET,polydopamine-coated PET.carboxyl-group-modified PET,and alkyl-group-modified PET.Upon water evaporation,the surface of the polydopamine-modified PET substrates can interact with the reduced graphene oxide sheets to form flattened and continuous RGO films,which exhibit a sheet resistance of 21.75 kΩ/sq at 82% transmittance.The result indicates that the properties of the surface groups determined whether uniform and flattened RGO films could be formed on the substrates.Hence,we proposed a simple and effective way to produce transparent and conductive films in which the catechol unit exhibits a great effect on the deposition of uniform RGO films on PET substrates.

High surface area, high catalytic activity titanium dioxide aerogels prepared by solvothermal crystallization

Titanium dioxide has been considered to be one of the most effective and environmental friendly photocatalytic material.It has been widely used in photocatalytic degradation of various pollutants.As we known,an anatase crystal form typically obtained by high temperature heat treatment(>600℃),usually shows higher catalytic activity.In order to further improve the catalytic efficiency,we prepared TiO2 with a non-supercritical drying method to form a high specific surface area aerogel structure,along with an increased active contact site.However,with the inevitable of internal pores collapse in the process of high temperature crystallization,a large amount of porous structure and specific surface area is reduced.Here,to enhance the photocatalytic activity of titania,we propose a synergistic strategy to fabricate a porous titania structure with a high specific surface area.It was crystallized at a lower temperature(120℃) in a low-boiling solvent(ethanol,acetone,etc.).The lattice structure was identified by X-ray diffractometry;specific surface area(over 300 m2/g) of our sample was also measured through BET test;in the subsequent photocatalytic degradation test,the photocatalytic degradation efficiency of fabricated TiO2 is proved to be more excellent than P25 powder.By a freeze-drying/mild crystallization method,a high-specific surface area and high catalytic activity TiO2 aerogel was synthetized.This study provides some insights in the combining of crystallization and high specific surface area of titanium dioxide photocatalysis.