| In recent years,the water pollution problem has become increasingly serious,Chlorophenols are highly toxic,dispersion and persistently stable in wastewater and posing a serious ecosystem hazard.Thus,it is particularly urgent to develop a sustainable technology to treat chlorophenols.Solar-based semiconductor photocatalysis technology has the advantages of simple reaction condition,strong redox capacity,and?-Fe2O3 has gained widespread attention as a low-cost,stable and non-toxic photocatalyst for chlorophenols degradation.However,it still suffers from poor charge separation,little specific surface area and hard recovery.In response to these issues,this paper focuses on the following studies:The synthesis of?-Fe2O3 nanotubes and the effect of SiO2 modification on photocatalytic activities were investigated.The phase separation electrospinning is developed to synthesize 1D porous?-Fe2O3 nanotubes,compared with nanoparticles,the degradation activities has been greatly improved,and the self-settling feature can effectively solve the problem of difficult recycling.Then,the in situ introduction of SiO2was developed for gaining small grain size of porous?-Fe2O3 nanotubes,and the photocatalytic activity is further enhanced.The SPS and O2-TPD tests showed that the primary reason for photocatalytic activity improved is due to the reduction of particle size and the increase of O2 adsorption,hence prolonging the life of photogenerated carriers and promoting their separation.The effect of degradation activity by coupling g-C3N4 on SiO2-introduced?-Fe2O3nanotubes was investigated.g-C3N4 was coupled on SiO2-modified?-Fe2O3 nanotubes by wet chemical method.EPR and single-wavelength photocurrent and N2 atmosphere SPS tests showed that the activity improvement is attributed to the effective formation of an"S"type charge transfer route between them,which promoted the separation of photogenerated carriers and improved the photocatalytic activity. |
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