Microwave Assisted Synthesis Of Chalcogenides Photothermal Materials And The Relationship Between Their Microstructures And Function

Photothermal materials have found a broad range of applications in diverse areas such as photothermal therapy,photothermal catalysis,solar cell and so on.Therefore,the development of more efficient photothermal materials has important impacts on both fundamental research and practical applications.Chalcogenide semiconductors have the advantages of low cost,good stability and the adjustable microstructure and compositions,when being compared with the high cost of precious metals,instability of organic materials,or poor photothermal efficiency of carbon materials,and therefore have very promising future among all existing photothermal materials.Studies have shown that Bi-and Cu-based chalcogenides and Te have attractive properties in optical absorption and photothermal conversion.In addition,Bi-based chalcogenides can be applied in the CT imaging,broadening its application to phototherapy.However,several problems remain to be solved,including complexity of the preparation procedure,poor photothermal conversion efficiency and few reported multi-components/functional materials.In this research one-step microwave-assisted synthesis is carried out to fabricate composite nanomaterials and subsequently optimize their nanostructures.Innovative results achieved through this research include:1?Using biocompatible Bi-and Cu-based chalcogenides as building block,multi-components Cu₂S/Bi₂S₃/Cu₃BiS₃ composites with strong optical absorption and bifunctionality was obtained through a simple one-step microwave assisted synthesis.Their microstructure,chemical compositions,and performance in photothermal conversion and CT imaging have been thoroughly characterized.The conversion efficiency of Cu₂S/Bi₂S₃/Cu₃BiS₃ was found to be 43.8%with greatly improved stability.CT angiography showed that the HU value in CT angiography was 16.7,which is better than the commercial Ultravisit 3000.2?Using a single precursor diethyldithiocarbamic acid tellurium?TDEC?,Te nanomaterials with a morphology of tube,wire and trifold have been fabricated through one-step microwave assisted synthesis.Their morphology,chemical compositions,optical absorption,and photothermal conversion were characterized carefully.Experiments illustrate that microstructure has great influence on their photothermal performance.In general,large surface area can improve the photothermal efficiency and the highest conversion rate in this study is 48.7%.In addition,a simple procedure is developed to coat Te particles with a thin layer of Au,which led to significant improvement to the optical absorption and photothermal properties of the materials.It is observed that materials with a tubular structure exhibits better thermalelectric performance than the other two groups of materials investigated.