Sepiolite/Cu2O/Cu photocatalyst: Preparation and high performance for degradation of organic dye

A novel ternary sepiolite/Cu₂O/Cu (SCC) nanocomposite was successfully synthesized by a facile one-pot method. The Cu₂O/Cu nanoparticles in the SCC nanocomposite are well dispersed on the sepiolite surface. It exhibited enhanced photocatalytic performance in the degradation of congo red (CR), remarkably superior to that of Cu₂O or Cu₂O/Cu nanoparticles. Elemental copper in the SCC serves as a good electron acceptor to promote the transfer of photo-generated electrons in Cu2O and suppress the recombination of the photo-generated electrons and holes of the composite. The enhanced photocatalytic efficiency is attributed to the synergistic effect of sepiolite and Cu₂O/Cu. This type of SCC nanocomposites is a promising candidate as photocatalytic material for environmental protection.     

Preparation and photocatalytic performance of CuO/GO heterojunction nanocomposite

Recently, solar photocatalytic technology has proved to be an effective way to solve the problems of environmental pollution and energy shortage due to its green environmental protection and fast degradation rate. In this paper, a simple microwave hydrothermal method is used to prepare a novel CuO/GO heterojunction composite photocatalyst, and its chemical composition, microstructure, physicochemical properties, photothermal conversion, and photocatalytic properties are studied. The results show that the addition of GO in the CuO/GO nanocomposite photocatalyst not only effectively reduces the agglomeration of CuO nanoparticles but also makes it exhibit better photocatalytic activity than pure nano-CuO. The degradation rate of MB increased by 39.48% at 120 min of light, and as high as 94.1% at 180 min, mainly due to the construction of heterojunction at the interface and the synergistic promotion effect of light and heat. The internal mechanism of light and heat synergistic catalysis is revealed. This paper not only proposes a low-cost and efficient CuO/GO light-heat composite photocatalyst but also provides new ideas for subsequent researchers to design and prepare nanocomposite photocatalysts.

     

Kinetic study of Cu(II) adsorption on nanosized BaTiO(3) and SrTiO(3) photocatalysts

In this study, nanoparticles with perovskite structure (nano-SrTiO(3) and nano-BaTiO(3)) were synthesized via a co-precipitation method, and their photocatalytic and adsorption characteristics were investigated. Both of them exhibited some photocatalytic activity and possessed a high adsorption capacity for copper ions. Further, the pseudo-first-order model was found to be more suitable to fit the experimental data. Moreover, it suggested that the Langmuir model was more adequate in simulating the adsorption isotherm. The maximum adsorption capacity was 370.4 mg/g and 200.0mg/g for nano-SrTiO(3) and nano-BaTiO(3), respectively. The negative apparent free energy confirmed that the Cu(2+) adsorption onto the nano-photocatalysts was a spontaneous process. The underlying mechanism of adsorption of Cu(II) onto nano-perovskites could be due to the ion exchange and surface complexation. From the results, SrTiO(3) and BaTiO(3) nanoparticles may be an effective material for Cu(2+) removal and, together with its photocatalytic activity, may be suitable for environmental remediation applications.     

J‐Aggregates of Organic Dye Molecules Complexed with Iron Oxide Nanoparticles for Imaging‐Guided Photothermal Therapy Under 915‐nm Light

Recently, the development of nano‐theranostic agents aiming at imaging guided therapy has received great attention. In this work, a near‐infrared (NIR) heptamethine indocyanine dye, IR825, in the presence of cationic polymer, polyallylamine hydrochloride (PAH), forms J‐aggregates with red‐shifted and significantly enhanced absorbance. After further complexing with ultra‐small iron oxide nanoparticles (IONPs) and the followed functionalization with polyethylene glycol (PEG), the obtained IR825@PAH‐IONP‐PEG composite nanoparticles are highly stable in different physiological media. With a sharp absorbance peak, IR825@PAH‐IONP‐PEG can serve as an effective photothermal agent under laser irradiation at 915 nm, which appears to be optimal in photothermal therapy application considering its improved tissue penetration compared with 808‐nm light and much lower water heating in comparison to 980‐nm light. As revealed by magnetic resonance (MR) imaging, those nanoparticles after intravenous injection exhibit high tumor accumulation, which is then harnessed for in vivo photothermal ablation of tumors, achieving excellent therapeutic efficacy in a mouse tumor model. This study demonstrates for the first time that J‐aggregates of organic dye molecules are an interesting class of photothermal material, which when combined with other imageable nanoprobes could serve as a theranostic agent for imaging‐guided photothermal therapy of cancer.     

Evaluating the life cycle environmental performance of chlorine disinfection and ultraviolet technologies

With increasing emphasis on promoting a sustainable ecological future and concern over introducing a toxic chemical in the water, the design of the disinfection process is increasingly leaning toward technologies that destroy the pathogens while balancing the effects of this disinfected wastewater on the population of aquatic biota or a drinking water supply. Since ultraviolet (UV) irradiation is not a chemical additive, it does not leave or produce any by-product toxic compounds in the wastewater, like traditional chlorination and de-chlorination processes do. Therefore, the use of UV does not affect a drinking water supply or the aquatic biota in receiving waters. Life cycle assessment or analysis (LCA) is used to quantify the environmental benefits of using UV disinfection technology (as well as better protecting public health), instead of chlorination and de-chlorination methods. LCA tools are being used to evaluate the short and long term environmental effects of both processes, and to select the best sustainable process. The approach here combines environmental LCA with these disinfection processes incorporating economic criteria and all aspects of the environment: chemical use, electricity use, and releases to water, air, and land. The environmental, health, and economic benefits and other effects show the greater sustainability of UV technology (a "clean" ecological disinfection process) in comparison to that of traditional disinfection with chlorine. Electronic Publication     

Sub‐10‐nm Pd Nanosheets with Renal Clearance for Efficient Near‐Infrared Photothermal Cancer Therapy

Efficient renal clearance is of fundamentally important property of nanoparticles for their in vivo biomedical applications. In this work, we report the successful synthesis of ultra‐small Pd nanosheets (SPNS) with an average diameter of 4.4 nm and their application in photothermal cancer therapy using a near infrared laser. The ultra‐small Pd nanosheets have strong optical absorption in the NIR region and high photothermal conversion efficiency (52.0%) at 808 nm. After being surface‐functionalized with reduced glutathione (GSH), the SPNS‐GSH was administered to mice to investigate the biodistribution, photothermal efficacy and tumor ablation in vivo. The in vivo photothermal therapy studies clearly demonstrate that surface modification with GSH allows the nanosheets to exhibit prolonged blood circulation and thus high accumulation in tumors. Upon 808 nm NIR irradiation, the tumors can be completely ablated. More importantly, with the size below the renal filtration limit (<10 nm), the GSHylated Pd nanosheets can be nicely cleared from body through the renal excretion route and into urine. Together with the high efficacy of NIR photothermal therapy, the unique renal clearance properties make the ultra‐small Pd nanosheets promising for practical use in photothermal cancer therapy.     

Photothermy-strengthened photocatalytic activity of polydopamine-modified metal-organic frameworks for rapid therapy of bacteria-infected wounds

Herein,a metal-organic framework(MOF)was modified using polydopamine(PDA)to develop the MOFPDA as a photoresponsive bacteria-killing agent under 660 nm light irradiation.The modification using PDA led to the production of not only more heat,but also much more~1O₂.This is because the PDA could interact with the porphyrin ring of the MOF throughπ-πinteraction and the charge transfer between PDA and the MOFs decreases the ene rgy of the band of hybrid nanoparticles.In addition,greater levels of hyperthermia induced by PDA modification accelerated the charge trans fe r,which significantly strengthened the photocatalytic perfo rmance of MO F-PDA.Furthermore,after modification,the light abso rbance and water dispersibility of nanoparticles were both enhanced;both are important for the improvement of photocatalytic and photothermal properties.Consequently,MOF-PDA exhibited the highly effective antibacterial efficacy of 99.62%and 99.97%against Staphylococcus aureus and Escherichia coli,respectively,under 20 min 660 nm light irradiation.     

Black Phosphorus,a Rising Star 2D Nanomaterial in the Post‐Graphene Era: Synthesis,Properties, Modifications,and Photocatalysis Applications

Semiconductor photocatalysis, a sustainable and renewable technology, is deemed to be a new path to resolve environmental pollution and energy shortage. The development of effective photocatalysts, especially the metal‐free photocatalysts, is a critical determinant of this technique. The recently emerged 2D material of black phosphorus with distinctive properties of tunable direct bandgap, ultrahigh charge mobility, fortified optical absorption, large specific surface area, and anisotropic structure has captured enormous attention since the first exfoliation of bulk black phosphorus into mono‐ or few layered phosphorene in 2014. In this article, the state‐of‐the‐art preparation methods are first summarized for bulk black phosphorus, phosphorene, and black phosphorus quantum dot and then the fundamental structure and electronic and optical properties are analyzed to evaluate its feasibility as a metal‐free photocatalyst. Various modifications on black phosphorus are also summarized to enhance its photocatalytic performance. Furthermore, the multifarious applications such as solar to energy conversion, organic removal, disinfection, nitrogen fixation, and photodynamic therapy are discussed and some of the future challenges and opportunities for black phosphorus research are proposed. This review reveals that the rising star of black phosphorus will be a multifunctional material in the postgraphene era.     

Architecting a bifunctional solar evaporator of perovskite La0.5Sr0.5CoO3 for solar evaporation and degradation

Solar-driven interfacial water evaporation can efficiently utilize abundant and sustainable solar energy to alleviate the scarcity of freshwater resources, which has been recognized as one of the most attractive technologies for purifying seawater and wastewater. However, photothermal evaporation process cannot eliminate pollutions in residual wastewater. Therefore, inducing photocatalytic degradation technology into photothermal evaporation will greatly realize the concurrent freshwater collection and pollution degradation. Herein, bifunctional La_0.5Sr_0.5CoO₃ (LSC5) solar evaporator with various architecture structures is constructed. It is demonstrated that the LSC5 photothermal catalyst has excellent solar absorption and photothermal conversion property. Furthermore, interpenetrating polyvinyl alcohol (PVA) and chitosan (CS) into LSC5 can promote water transport capacity and decrease water evaporation enthalpy. Benefited from these advantages, three-dimensional (3D) solar evaporator comprised of LSC5 and PVA/CS polymer achieves a relatively high evaporation rate of 2.45 kg m^?2 h^?1 with the photothermal conversion efficiency of 93.0%. Moreover, the LSC5 displays obvious photocatalytic degradation effect on tetracycline pollutants. Therefore, this photothermal–photocatalytic degradation bifunctional hydrogel provides a promising alternative material for comprehensive water purification and pollution elimination.

     

Construction of Infrared-Light-Responsive Photoinduced Carriers Driver for Enhanced Photocatalytic Hydrogen Evolution

Infrared light, more than 50% of the solar light energy, is long-termly ignored in the photocatalysis field due to its low photon energy. Herein, infrared-light-responsive photoinduced carriers driver is first constructed taking advantage of pyroelectric effect for enhancing photocatalytic hydrogen evolution. In order to give full play to its role, the photocatalytic reaction is localized on the surface and interface of the composite based on a new semi-immersion type heat collected photocatalytic microfiber system. The system is consisted of distinctive pyroelectric substrate poly(vinylidene fluoride-co-hexafluropropylene (PVDF-HFP), typical photothermal material carbon nanotube (CNT), and representative photocatalyst CdS. The transient photocurrent, electrochemical impedance spectroscopy, time-resolved photoluminescence and pyroelectric potential characterizations indicate that the infrared-light-responsive carriers driver significantly promotes the photogenerated charge separation, accelerates carrier migration, and prolongs carrier lifetime. The photocatalytic hydrogen evolution efficiency is remarkably improved more than five times with the highest average apparent quantum yield of 16.9%. It may open up new horizons to photocatalytic technology for the more efficient use of infrared light.     

Phosphorene-Based Heterostructured Photocatalysts

Semiconductor photocatalysis is a potential pathway to solve the problems of global energy shortage and environmental pollution. Black phosphorus (BP) has been widely used in the field of photocatalysis owing to its features of high hole mobility, adjustable bandgap, and wide optical absorption range. Nevertheless, pristine BP still exhibits unsatisfactory photocatalytic activity due to the low separation efficiency of photoinduced charge carriers. In recent years, the construction of heterostructured photocatalysts based on BP has become a research hotspot in photocatalysis with the remarkable improvement of photoexcited charge-separation efficiency. Herein, progress on the design, synthesis, properties, and applications of BP and its corresponding heterostructured photocatalysts is summarized. Furthermore, the photocatalytic applications of BP-based heterostructured photocatalysts in water splitting, pollutant degradation, carbon dioxide reduction, nitrogen fixation, bacterial disinfection, and organic synthesis are reviewed. Opportunities and challenges for the exploration of advanced BP-based heterostructured photocatalysts are presented. This review will promote the development and applications of BP-based heterostructured photocatalysts in energy conversion and environmental remediation.     

新型聚多巴胺纳米颗粒光热蒸发性能评价

聚多巴胺具有与黑色素相似的吸光性能,是一种被广泛关注的高分子近红外吸收材料,在光热转化方面有良好前景。但由于其本身聚合机理多样,内部结构复杂,目前对聚多巴胺功能性设计的研究较少。本文通过设计Fe³⁺和硅烷偶联剂与多巴胺反应,提高了聚多巴胺的吸光特性和亲水性;通过X射线光电子能谱(XPS)、傅里叶变换红外光谱(FTIR)等表征证明,成功合成了高吸光度亲水聚多巴胺纳米颗粒,吸光度达到90%。同时将合成的纳米颗粒真空抽滤,堆叠构建亲水输运通道。实验表明：在太阳光蒸发环境,一个太阳光强下,使用本文设计的光热膜进行纯水蒸发实验,纯水蒸发速率可以达到1.1 kg/(m²·h),光热转化效率为80%,比普通聚多巴胺提高15%,证明该材料有很好的光热转化性能,在海水淡化领域有着良好的应用前景。     

Cu nanoparticle-decorated two-dimensional carbon nanosheets with superior photothermal conversion efficiency of 65 ％ for highly efficient disinfection under near-infrared light

Low photothermal conversion efficiency restricts the antibacterial application of photothermal materials.In this work,two-dimensional carbon nanosheets (2D C) were prepared and decorated with Cu nanopar-ticles (2D C/Cu) by using a simple soluble salt template method combined with ultrasonic exfoliation.The photothermal conversion efficiency of 2D C/Cu system can be optimized by changing the content of Cu nanoparticles,where the 2D C/Cu2 showed the best photothermal conversion efficiency (η) of 65.05％ under 808 nm near-infrared light irradiation.In addition,the photothermal performance can affect the release behavior of Cu ions.This superior photothermal property combined with released Cu ions can endow this 2D hybrid material with highly efficient antibacterial efficacy of 99.97 ％ ± 0.01％,99.96 ％ ±0.01％,99.97 ％ ± 0.01％ against Escherichia coli,Staphylococcus aureus,and methicillin-resistant Staphylo-coccus aureus,respectively,because of the synergetic effect of photothermy and ion release.In addition,this 2D hybrid system exhibited good cytocompatibility.Hence,this study provides a novel strategy to enhance the photothermal performance of 2D materials and thus will be beneficial for development of antibiotics-free antibacterial materials with safe and highly efficient bactericidal activity.     

Facile synthesis of hydrophilic polypyrrole nanoparticles for photothermal cancer therapy

PPY nanoparticles, as one of the important organic photothermal agents has been attracted great attention due to their good biocompatibility, high photothermal efficiency, and low cost. In order to further evaluate the size-dependent photothermal effect, PPY nanoparticles with two different sizes have been prepared with a facile method. The near infrared absorption and photothermal effect of the two size PPY nanoparticles were compared. The PPY nanoparticle with small size shows better photothermal effect at the same condition. The photostability, stability, and cytotoxicity in biologic system have also been investigated. In addition, the PPY nanoparticles with small size can kill the cancer cells effectively under the irradiation of 808 nm laser with a low-power density. These findings may provide better information for the application of the PPY nanoparticles on the photothermal ablation of cancer cells.     

淀粉/聚乳酸共混可降解材料研究进展

介绍了淀粉在可降解塑料中应用的发展历史和现状,阐述了近几年国内外淀粉/聚乳酸共混体系的研究进展.以期在该领域里能更好、更快的开发出可替代传统塑料的可降解材料,以解决目前人类面临地并日益突出地环境问题和能源危机.     

普鲁士蓝/氟化超支化聚氨酯复合涂层材料及其光热转换超疏水性能

首先制备氟化超支化聚氨酯(FHPU),然后与具有光热转化功能的普鲁士蓝(PB)纳米粒子复合,得到光热转换功能的PB/FHPU超疏水防结冰复合涂层材料。利用FTIR、TGA和DSC等测试分析了FHPU和PB/FHPU超疏水防结冰复合涂层材料的结构及性能,通过光热转换实验证明了复合涂层材料出色的光热性能;深入探究了PB纳米粒子的添加量对复合涂层材料表面性质和光热转化性能的影响。结果表明,当PB质量占FHPU的13%时,复合涂层材料可形成具有微纳结构的复合涂层,涂层表面最大接触角达157°,滚动角为1.8°。同时,该涂层在808 nm激光照射下10 s内温度可升高78.1℃,最高温度达到148.7℃。因而,光热转换功能性超疏水防结冰复合涂层材料具有良好的疏水、防结冰性能。      

Photocatalytic activity of erbium-doped TiO2 nanoparticles immobilized in macro-porous silica films

A macro-porous silica film served as mechanical support to immobilize TiO₂ nanoparticles, which were doped with erbium. The films and the nanoparticles were prepared by sol–gel route. The nanoparticles exhibited photocatalytic activity under visible light. We obtained a degradation rate of methylene blue that followed first order kinetics. The sensitization of the nanoparticles to visible light was attributed to a red shift in the band-gap of the TiO₂ due to the addition of erbium ions.     

Nanotechnological medical devices and nanopharmaceuticals: the European regulatory framework and research needs

The European regulatory framework is examined in relation to nanotechnology based medical devices and medicinal products. Medical applications of nanotechnology will have to comply with the requirement for a high level of public health, safety, consumer, and environmental protection. An evaluation of the possible health or environmental risks of nanoparticles must therefore be carried out and it is important to ensure that particle size and chemistry are taken into account when investigating possible adverse effects. Further research is needed on the toxicological and ecotoxicological properties of nanoparticles, their uptake in the body, accumulation in tissues and organs, transport characteristics, exposure and dose-response data, and their distribution and persistence in the environment. The existing regulations appear adequate to manage the risks of nanotechnology at its current stage of development but continuous review of the regulatory regime will be needed to determine whether it is sufficient to protect human health and the environment. Modification of the legislation may prove necessary as new scientific evidence emerges regarding the effects of nanoparticles on living organisms and in the ecosystems.     

Highly Dispersed RuOOH Nanoparticles on Silica Spheres:An Efficient Photothermal Catalyst for Selective Aerobic Oxidation of Benzyl Alcohol

Photothermal catalysis represents a promising strategy to utilize the renewable energy source(e.g.,solar energy)to drive chemical reactions more efficiently.Successful and efficient photothermal catalysis relies on the availability of ideal photothermal catalysts,which can provide both large areas of catalytically active surface and strong light absorption power simultaneously.Such duplex requirements of a photothermal catalyst exhibit opposing dependence on the size of the catalyst nanoparticles,i.e.,smaller size is beneficial for achieving higher surface area and more active surface,whereas larger size favors the light absorption in the nanoparticles.In this article,we report the synthesis of ultrafine RuOOH nanoparticles with a size of 2–3 nm uniformly dispersed on the surfaces of silica(SiOx)nanospheres of hundreds of nanometers in size to tackle this challenge of forming an ideal photothermal catalyst.The ultrasmall RuOOH nanoparticles exhibit a large surface area as well as the ability to activate adsorbed molecular oxygen.The SiOx nanospheres exhibit strong surface light scattering resonances to enhance the light absorption power of the small RuOOH nanoparticles anchored on the SiOx surface.Therefore,the RuOOH/SiOx composite particles represent a new class of efficient photothermal catalysts with a photothermal energy conversion efficiency of 92.5%for selective aerobic oxidation of benzyl alcohol to benzylaldehyde under ambient conditions.     

Aggregation-Induced Emission Luminogens Married to 2D Black Phosphorus Nanosheets for Highly Efficient Multimodal Theranostics

Inspired by the respective advantages of aggregation-induced emission (AIE)-active photosensitizers and black phosphorus nanomaterials in cancer treatment, the facile construction of novel AIE photosensitizers married to 2D black phosphorus nanosheets and their application for multimodal theranostics are demonstrated. The developed nanomaterial simultaneously possesses distinctive properties and multiple functions including excellent stability, good biocompatibility, intensive fluorescence emission in the NIR region, high-performance reactive oxygen species generation, good photothermal conversion efficiency, outstanding cellular uptake, and effective accumulation at the tumor site. Both in vitro and in vivo evaluation show that the presented nanotheranostic system is an excellent candidate for NIR fluorescence–photothermal dual imaging-guided synergistic photodynamic–photothermal therapies. This study thus not only extends the applications scope of AIE and black phosphorus materials, but also offers useful insights into designing a new generation of cancer theranostic protocol for potential clinical applications.