Preparation And Applications Of Flower-like CuS Composites

Nanomaterials have unique advantages in solving the problem of energy and environment in comparison with conventional materials due to its` special optical,electricity,magnetic,thermal,mechanical and other physicochemical properties,which thus have drawn extensive attentions in the world wide.Especially for recent years,nanocomposites have been designed and developed,which can coordinate the advantages of multiphase materials to further expand their applications in numerous fields.Researches on semiconducting copper sulfide(CuS)have been rapidly expanded due to its optical,electronic and other excellent physical and chemical properties with modern applications such as photothermal conversion,nanometer scale switches,solar cell devices and lithium-ion batteries.Graphene as a novel two-dimensional carbon material has been widely used in many fields including electrodes,transparent thin films and polymer composite fillers due to excellent properties such as large specific surface area,high mobility of charge carriers and excellent thermal conductivity.Polyaniline(PANI),as a typical conducting polymer,is one of the most promising conducting polymers with excellent physical and chemical properties.After introducing second phase such as metals or carbons into polymeric matrix,the new formed conductive network of different materials is in favor of electrons free to move in polymers and further improve the dielectric constant of the polymer,which thus can expand its` applications in many fields.In this paper,flower-like CuS and CuS/RGO composites were fabricated via a facile one-step solvothermal method for the purpose of photocatalytic,UV protection and EMI shielding applications;And PANI/flower-like CuS and PANI/CuS/RGO composites with enhanced electromagnetic interference(EMI)shielding effectiveness(SE)wereV also prepared via in-situ polymerization.The main results are listed below:(1)The flower-like CuS hierarchical structures were synthesized by solvothermal method.The as-prepared products were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transform infrared(FTIR)spectroscopy,UV–vis optical absorption spectroscopy,Malvern Zetasizer and thermogravimetric analysis(TGA).The results demonstrated that the as-prepared flower-like CuS with the diameter of 1–5 um was pure hexagonal phase CuS and had well-defined flower-like structures.(a)The as-prepared CuS was proved to possess high photocatalytic performance with band gap of 1.45 eV.The degradation rate of Methylene blue(MB)was up to,98.26%,100% after 30 min under UV and visible irradiation.(b)The UPF of cotton fabric treated with CuS reached up to 174 compared with the original untreated fabric with the UPF 20.62.(c)The electromagnetic interference shielding effectiveness(EMI SE)of CuS coating was up to-27 dB~–31 dB when the content of CuS increased to 28.6wt% in the frequency of 300 KHz ~ 3 GHz.Furthermore,the influence of reaction conditions on the morphology of the as-prepared CuS was investigated systematically and the possible formation mechanism of the CuS hierarchical structure was also proposed.(2)The flower-like CuS/RGO composites were fabricated via a facile one-step solvothermal method,which displayed outstanding photocatalytic activity for MB degradation.The composition and structure of the prepared composites were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Raman spectra,photoluminescence(PL)spectra,scanning electron microscopy(SEM),Transmission electron microscope(TEM),Malvern Zetasizer and UV-vis optical absorption spectroscopy.The results showed that RGO had significantly influence on the photocatalytic performance.Compared with pristine CuS,flower-like CuS/RGO composites exhibited enhanced photocatalytic activity and excellent recyclability for the photodegradation of Methylene blue(MB)with degradation efficiency of nearly100% in 140 min under Xenon lamp irradiation,which was 4 times greater than that of CuS,indicating that CuS/RGO could be acknowledged as a promising photocatalyst for the removal of organic contaminants.(3)The novel PANI/flower-like CuS composites with improved electromagnetic interference(EMI)shielding effectiveness(SE)were prepared through in-situ polymerization of PANI into the flower-like CuS microspheres.X-ray diffraction(XRD),scanning electron microscopy(SEM),Transmission electron microscope(TEM),Fourier transform infrared(FTIR)spectroscopy,UV-vis optical absorption spectroscopy,thermogravimetric analysis(TGA),electrical conductivity and EMI SE were used to characterize the as-obtained products.The results revealed that flower-like CuS was uniformly coated by the PANI shell.Most importantly,compared with original CuS and pure PANI,the novel PANI/flower-like CuS composites exhibited remarkably enhanced shielding effectiveness.With a thickness of 3 mm,the optimal EMI SE of PANI/ CuS composites reached-45.2 dB at 2.78 GHz and the improved shielding efficiency below-18 dB was also obtained over the frequency range of 300 KHz ~ 3 GHz,suggesting that this novel PANI/flower-like CuS composites showed a promising application in the field of shielding materials.(4)The PANI/CuS/RGO composites with improved electromagnetic interference(EMI)shielding effectiveness(SE)were prepared through in-situ polymerization of PANI into surface of CuS/RGO.X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),Transmission electron microscope(TEM),Fourier transform infrared(FTIR)spectroscopy,Thermogravimetric(TG)analysis were used to characterize the as-obtained products.Compared with original PANI,the PANI/CuS/RGO exhibited remarkably enhanced shielding effectiveness.With a thickness of 3 mm,the average EMI SE of composites reached up to-18 dB from-7.5 dB in the frequency range of300 KHz ~ 3 GHz,suggesting that this novel PANI/CuS/RGO composites with lightweight and high efficiency properties had a promising application in the field of electromagnetic shielding materials.