The Fabrication And Photocatalytic Performance Of Silver-Indium-Sulfide-based Photocatalyst

The broad application of photocatalysts in the fields of photovoltaics,optoelectronics, photocatalysis guarantee the photocatalytic technology superiority to settle the current environment, energy and sustainable development issues.Based on Silver-Indium-Sulfide-based photocatalyst research, this paper aims to the preparation and modification of photocatalysts, the control of unit process and the growth mechanism and photocatalytic mechanism to widen its application.Considering theses, a simple low-temperature co-precipitation method was adopted to synthesis AgInS2, with visible-light driven, high catalytic activity and strong mineralization capability. In addition to, the functionalized carbon nanotube dispersion(f-MWCNT) and mesoporous carbon nitride(mpg-C3N4) were introduction to AgIn5S8(AIS) to decorate the catalyst, tailor the band structure and improve the photocatalytic efficiency. The contents and conclusions are summarized as follows:Preparation and photocatalytic performance of Indium-rich AgInS2 photocatalyst with narrow band gap. AgNO3, In(Cl)3?4H2O, thioacetamide(TAA) were used as the main raw materials, and the reaction temperature, the solvent, TAA contents and the In/Ag molar ratio in the precursor were controlled in the experiments to optimize the synthesize strategy. A series of characteristic techniques were used to analysis the phase, morphology, structure, adsorption, photoelectric performance of products.Besides, MO and 2-NP were chosen as model pollutants to evaluate the photodegradation property and speculate the photodegradation mechanism. What’s more, the In/Ag molar ratio in the precursor was found to be related to the morphology, photoelectric and photocatalytic performance to some extent. When the molar ratio of In/Ag was 9, the band gap was 1.62 eV, the photocurrent density was 11μA?cm-2, while the PL intensity reached the lowest. The thermal stability and photocatalytic property of AgInS2(In/Ag = 9) surpass other products prepared in the same condition, which may be ascribed to the synergy effect between the Ag+- In3+precursor and the solvent, the strong response to the visible light, the narrow band gap and the most efficient separation with electron-hole.Preparation and photocatalytic performance of AgIn5S8 and modified AgIn5S8co-photocatalyst(CNT/AIS, g-C3N4/AIS). With AgNO3, In(NO3)3?xH2O and thioacetamide as the main raw materials, water as the solvent, a low-temperatureco-precipitation method was used to prepare cubic spinel phase AIS photocatalyst. By analysising the crystal phase, morphology, hydrodynamic size and EIS of products fabricated with different reaction time, the crystal growth mechanism was also studied.Then, functionalized carbon nanotube(f-MWCNT) and mesoporous carbon nitride(mpg-C3N4) were in-situ introduction to AIS to decorate the catalyst, tailor the band structure and improve the photocatalytic efficiency. The optimum ratio of modifier to AIS were both 3wt%. Composites exhibited excellent catalytic performance, probably due to the fact that f-MWCNT served as an electron acceptor, improving electron transport speed and ability; while mpg-C3N4 and AIS with matched band structure grown heterojunction material, thereby upgrading the catalytic activity of AIS.