BiOBr/Bi复合光热粉体的制备及其界面光热驱动水蒸发性能

针对太阳能转化应用,溴氧化铋(BiOBr)光催化性能优异,但其光热性能及应用有待研究开发。首先采用水热法制备了BiOBr纳米片粉末,然后利用硼氢化钠(NaBH₄)对BiOBr粉末进行化学还原。样品表征结果显示,随着硼氢化钠浓度增加,致密的BiOBr纳米片首先转变为BiOBr/Bi复合多孔纳米片,然后转变为金属Bi多孔纳米片。金属Bi及多孔结构的形成有助于提升材料的光吸收性能及比表面积。经过20 g·L^-1 NaBH₄溶液还原得到的BiOBr/Bi多孔纳米片具有最优的光吸收性能和比表面积,且润湿性能优异。光热驱动水蒸发测试结果表明,20 g·L^-1 NaBH₄还原得到的BiOBr/Bi复合多孔纳米片具有最优的光热驱动水蒸发性能,水蒸发速率可达2.18 kg·m^-2·h^-1,为纯BiOBr纳米片的2倍。     

石墨烯/碳纳米管复合气凝胶制备及其光热蒸发性能评价

石墨烯作为一种二维碳基纳米材料,具有宽光吸收范围、高的比表面积、优异的导热导电性及机械性能,在光热转换应用方面具有良好前景。为进一步增强石墨烯的吸光性能,减少石墨烯片层间的团聚,引入一维的碳纳米管,采用简单的水热还原法制备了石墨烯/碳纳米管复合气凝胶三维光热材料,其比表面积显著增强、表面更加粗糙,且具有开放的微观孔道结构。扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶红外光谱(FT-IR)等表征发现,石墨烯与碳纳米管实现了有效复合。以紫外-可见-近红外分光光度计(UV-vis-NIR)对材料进行了光吸收能力评价,结果证明石墨烯/碳纳米管复合气凝胶在200～2 500 nm区间内吸光度可达92%。将复合气凝胶置于人工海水上进行光热蒸发评价,发现对人工海水的蒸发速率可达2.287 kg·m~(-2)·h~(-1),光热转换效率达96.88%,说明该石墨烯/碳纳米管复合气凝胶具有良好的光热转化性能,在海水淡化方面具有广阔的应用前景。     

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。      

CNTs-HEC/PVDF多孔复合膜增强太阳能界面水蒸发

太阳能界面水蒸发技术在解决目前人类所面临的能源和淡水资源短缺方面具有广阔的应用前景。水输运是太阳能水蒸发过程中十分重要的一环。理想状态下的水输运是输送适量的水来维持太阳能蒸发层高效、稳定的水蒸发。而蒸发层所拥有的多孔结构所产生的毛细管作用力决定了其水输运的能力。因此，蒸发层内部的孔隙结构非常重要。本文以聚偏氟乙烯(PVDF)为基体，借助碳纳米管(CNTs)的优异光吸收能力，通过羟乙基纤维素(HEC)掺杂并与戊二醛进行交联制备了可用于太阳能界面水蒸发的CNTs-HEC/PVDF多孔复合膜。CNTs-HEC/PVDF复合膜的多孔结构形成的微通道提高了水输运和蒸汽逸出能力，从而增强了太阳能界面水蒸发性能。在1 kW·m^-2的太阳光照射下，其水蒸发速率达到1.81 kg·m^-2·h^-1，相应的光热转化效率为95%。相关实验结果还展现出该复合膜具有优异的循环使用性能、化学稳定性和高效的污水净化能力。     

用于高性能太阳能界面蒸发的织物交错复合水凝胶（英文）

二维织物材料已广泛应用于太阳能界面蒸发,然而织物基太阳能蒸发器要实现吸光材料与纤维之间的强相互作用,高效的输水能力,优异的脱盐性能和高蒸发率仍然具有挑战性.我们制备了一种织物交错复合水凝胶(FICH)用于高效的太阳能界面蒸发.由于酸化碳纳米管均匀分布在水凝胶中并与大分子链形成氢键,水可以通过超亲水织物连续泵入复合水凝胶中,从而降低水的蒸发焓.薄型FICH蒸发器具有优异的光热转换性能,具有高蒸发速率(2.47 kg m² h^-1),强耐盐性,长期蒸发稳定性和耐久性.此外,FICH可以用于腐蚀性溶液和乳液的净化,在太阳能海水淡化中显示出广阔的应用前景.     

曝气辅助聚多巴胺共沉积膜的制备与表征

聚偏氟乙烯(PVDF)膜具有良好的物理化学稳定性和分离性能,以提升PVDF膜亲水性为目标的膜材料改性研究一直是膜研究的重点.聚多巴胺/聚乙烯亚胺(PDA/PEI)共沉积法可生成性能优异的亲水涂层,是制备亲水膜的重要方法.本研究针对疏水PVDF中空纤维膜的亲水改性,建立了曝气辅助PDA/PEI共沉积法,为多巴胺/聚乙烯亚胺(DA/PEI)溶液提供富氧环境,加快DA和PEI的反应速率,实现疏水中空纤维膜快速亲水化.相比于静置沉积,曝气辅助共沉积体系能够在反应90 min后获得性能良好的亲水改性膜.曝气辅助沉积改性膜接触角为45.3°,纯水通量为201.2 L/(m²·h),渗透性能显著提升;改性膜具有优异BSA截留率.     

研发双层结构的碳基水凝胶材料提高太阳能水蒸发效率（英文）

太阳能水蒸发对于解决净水危机潜力无限.随着研究的深入,研发高效光热转换材料和合理的材料结构设计均可以提高光热蒸发速率.因此,我们设计合成了一种双层碳基水凝胶复合材料.在一个太阳光照条件下,其最大蒸发速率可达2.19 kg m^-2 h^-1,光热转换效率可达93.7%.同时,该复合材料展现了优异的海水淡化性能及良好的稳定性,扩展了实际应用范围.除此之外,其可控规模化及便携性可以自如面对多种复杂的应用环境,成本低廉可以使其大规模应用于经济落后地区,为复合结构水凝胶蒸发器的生产提供了可供参考的设计思路和策略.     

柔性多孔硅橡胶负载纳米CuS的太阳能蒸发性能研究

界面太阳能蒸发是一种高效、低成本的水净化技术,光热转换材料、微观结构热管理是实现高效太阳能驱动蒸汽产生的关键.聚二甲基硅氧烷(PDMS)是一种环保且结构可灵活设计的柔性硅橡胶,通过填料可有效改善硅橡胶的热导率系数.纳米硫化铜(CuS)在近红外光几乎100％吸收,是一种新型的光热转换材料.本工作以方糖为模板、纳米二氧化硅(SiO2)和铝粉(Al)为填料制备了多孔的SiO2-PDMS/PDMS-Al双层硅橡胶,分别构建隔热、导热层,通过聚乙烯醇(PVA)将纳米CuS附着于PDMS-Al层作为光热转换材料.这种硅橡胶复合材料不仅提高了光热转换材料的亲水性,太阳光吸收率达到97.3％,在1 kW/m2光照下能获得77.03％的蒸发效率,而且具有良好的循环稳定性.PDMS复合光热材料从微观结构上减少了界面太阳能蒸发过程中的热损失,对推广该技术应用于海水淡化、污水处理等具有重要的意义.     

多层结构聚丙烯酰胺水凝胶太阳能蒸发器的制备及性能

优化设计太阳能蒸发器的结构并提高光热转换效率是改善其蒸发性能的有效途径。本工作基于原位自由基聚合反应,设计了一种多层结构的聚丙烯酰胺(PAM)复合水凝胶太阳能蒸发器并研究了其性能。该水凝胶由底部PAM/纳米纤维素(PAM/CNF)水运输层、中部PAM/碳纳米管/氮化钛(PAM/CNTs/TiN)光热转换层以及顶部“孤岛”状PAM/空心MXene微球(PAM/HSMX)构成的粗糙表面层组成。这种设计构建的PAM/CNF-PAM/CNTs/TiN-PAM/HSMX多层结构水凝胶太阳能蒸发器(ML-SVG)不仅能够提高光热转换效率,减少热量的损耗,而且促进了水分的运输,从而赋予ML-SVG优良的蒸发性能。ML-SVG在2kW·m^-2太阳光照射下的蒸发速率达到2.2kg·m^-2·h^-1,同时具有优良的循环使用性能,高效的污水净化和盐水淡化性能。     

纳米SiO2-氧化石墨烯/聚偏氟乙烯杂化膜的制备及特性

采用原位水解的方式制备了新型SiO₂-氧化石墨烯（GO）纳米杂化颗粒。选择GO、SiO₂、SiO₂-GO颗粒和聚乙烯吡咯烷酮（PVP）为添加剂,采用浸没沉淀相转化法分别制备了聚偏氟乙烯（PVDF）杂化膜。测定了PVDF杂化膜的纯水通量、膜面接触角、牛血清白蛋白（BSA）截留率和污染恢复率等参数。结果表明,SiO₂-GO/PVDF-PVP膜的接触角从78.4°减小到66.02°,膜的亲水性能有所提升。同时,SiO₂-GO/PVDF-PVP膜的纯水通量最大（1 018 L/（m²·h））,对BSA的截留率达到81.5%,污染恢复率达到了78.65%以上。新型SiO₂-GO纳米杂化颗粒协同PVP添加剂增强了PVDF超滤膜的水通量、污染物截留和抗污染特性等综合性能,为传统PVDF有机膜的改性提供了一种新方法。     

Biradical-Featured Stable Organic-Small-Molecule Photothermal Materials for Highly Efficient Solar-Driven Water Evaporation

With recent progress in photothermal materials, organic small molecules featured with flexibility, diverse structures, and tunable properties exhibit unique advantages but have been rarely applied in solar-driven water evaporation owing to limited sunlight absorption resulting in low solar–thermal conversion. Herein, a stable croconium derivative, named CR-TPE-T, is designed to exhibit the unique biradical property and strong π–π stacking in the solid state, which facilitate not only a broad absorption spectrum from 300 to 1600 nm for effective sunlight harvesting, but also highly efficient photothermal conversion by boosting nonradiative decay. The photothermal efficiency is evaluated to be 72.7% under 808 nm laser irradiation. Based on this, an interfacial-heating evaporation system based on CR-TPE-T is established successfully, using which a high solar-energy-to-vapor efficiency of 87.2% and water evaporation rate of 1.272 kg m⁻² h⁻¹ under 1 sun irradiation are obtained, thus making an important step toward the application of organic-small-molecule photothermal materials in solar energy utilization.     

Biosynthesis of Melanin Nanoparticles for Photoacoustic Imaging Guided Photothermal Therapy

Photothermal therapy (PTT) has attracted considerable attention in recent years due to their unique advantages in minimal invasiveness and spatiotemporal selectivity. However, the fabrication procedures of PTT agents frequently require complex chemical and/or physical methods that involves harsh and environmentally hazardous conditions. Here, a genetically engineered bacterium is developed to synthesize melanin nanoparticles under mild and environmentally friendly conditions. The biosynthetic melanin nanoparticles exhibit excellent biocompatibility, good stability, and negligible toxicity. In addition, the biosynthetic melanin nanoparticles have strong absorption at near-infrared (NIR) region and higher photothermal conversion efficiency (48.9%) than chemically synthesized melanin-like polydopamine nanoparticles under an 808 nm laser irradiation. Moreover, the results show that the biosynthetic melanin nanoparticles have excellent photoacoustic imaging (PAI) performance and can be used for PAI guided PTT in vivo. In conclusion, the study provides an alternative approach to synthesize PTT agents with broad application potential in the diagnosis and treatment of cancer.     

Incorporating Chaotropic/Kosmotropic Chemistries onto Plasmonic Nanoheater to Boost Steam Generation Beyond its Photothermal Property

Photothermal steam generation promises decentralized water purification, but current methods suffer from slow water evaporation even at high photothermal efficiency of ≈98%. This drawback arises from the high latent heat of vaporization that is required to overcome the strong and extensive hydrogen bonding network in water for steam generation. Here, light-to-vapor conversion is boosted by incorporating chaotropic/kosmotropic chemistries onto plasmonic nanoheater to manipulate water intermolecular network at the point-of-heating. The chaotropic-plasmonic nanoheater affords rapid light-to-vapor conversion (2.79 kg m⁻² h⁻¹ kW⁻¹) at ≈83% efficiency, with the steam generation rate up to 6-fold better than kosmotropic platforms or emerging photothermal designs. Notably, the chaotropic-plasmonic nanoheater also lowers the enthalpy of water vaporization by 1.6-fold when compared to bulk water, signifying that a correspondingly higher amount of steam can be generated with the same energy input. Simulation studies unveil chaotropic surface chemistry is crucial to disrupt water hydrogen bonding network and suppress the energy barrier for water evaporation. Using the chaotropic-plasmonic nanoheater, organic-polluted water is purified at ≈100% efficiency, a feat otherwise challenging in conventional treatments. This study offers a unique chemistry approach to boost light-driven steam generation beyond a material photothermal property.     

Drug‐Controlled Release Based on Complementary Base Pairing Rules for Photodynamic–Photothermal Synergistic Tumor Treatment

Controlled drug release systems can enhance the safety and availability but avoid the side effect of drugs. Herein, the concept of DNA complementary base pairing rules in biology is used to design and prepare a photothermal‐triggered drug release system. Adenine (A) modified polydopamine nanoparticles (A‐PDA, photothermal reagent) can effectively bind with thymine (T) modified Zinc phthalocyanine (T‐ZnPc, photosensitizer) forming A‐PDA = T‐ZnPc (PATP) complex based on A = T complementary base pairing rules. Similar to DNA, whose base pairing in double strands will break by heating, T‐ZnPc can be effectively released from A‐PDA after near infrared irradiation–triggered light‐thermal conversion to obtain satisfactory photodynamic–photothermal synergistic tumor treatment. In addition, PDA can carry abundant Gd³⁺ to provide magnetic resonance imaging guided delivery and theranostic function.     

Preparation and properties of cotton stalk carbon/gold nanoparticles composite

In this paper, cotton stalk is used as a low-cost raw material source to prepare activated carbon with a unique porous structure with the assistance of chemical treatment. Gold nanoparticles as a multifunction building block were in situ assembled onto the carbon material, endowing this hybrid more promising applications. The as-fabricated CS carbon/AuNPs hybrid materials have been demonstrated to behave with catalytic and photothermal conversion properties, indicating that AuNPs successfully functionalise the activated carbon. The catalytic activity of the hybrid showed a glucose concentration-dependent effect (as low as 5 × 10^?6 M). The water temperature of the sample containing the CS carbon/Au NPs increased rapidly, and even reached 55 °C, only exposed to light for 5 min. When used as catalyst of reduction of p-nitrophenol, the hybrid showed a good reusability up to10 cycles.     

808 nm triggered multifunctional UCNPs@PDA nanocomposites for temperature sensing and photothermal conversion

Multifunctional nanoparticles with marvelous temperature sensing and photothermal conversion are preferable in photothermal therapeutic applications. Herein, nanocomposites of NaYF₄:Er³⁺/Yb³⁺@NaYF₄:Nd³⁺/Yb³⁺ core–shell upconversion nanoparticles (UCNPs) modified by polydopamine (PDA) were designed to achieve temperature sensing and efficiency of photothermal conversion. It has been found that under the irradiation of 808 nm laser, temperature sensing can be realized on the basis of the fluorescence intensity ratio of Er³⁺ green light emission. In addition, the photothermal conversion ability of the UCNPs modified by PDA is greatly improved. Moreover, Nd³⁺ as activator endows UNCPs excited by 808 nm, which can avoid overheating due to the absorption of the excitation band (980 nm) in water. Therefore, the multifunctional nanoparticles are expected to become an effective drug for cancer therapy in the future and this research will stimulate interest in designing multifunctional nanoparticles that are biocompatible, especially for in vivo tumor diagnosis.

     

双糖聚合物接枝金纳米星的制备及光热性能研究

通过酶促反应和可逆加成-断裂链转移聚合(RAFT)聚合得到温度敏感性的双糖无规聚合物聚(二聚乙二醇单甲醚甲基丙烯酸酯-6-O-乙烯基己二酸-D-吡喃型葡萄糖/半乳糖酯)[Poly(DEGMA-co-OVNGmix)];利用还原剂将聚合物末端的硫酯键还原,得到末端为-SH的聚合物分子以S-Au键修饰到金纳米星表面。采用傅里叶红外光谱仪、透射电镜和核磁氢谱等手段对聚合物和复合金纳米星的理化性质和光热转化能力进行研究。结果表明:AuNSs@Poly(DEGMA-co-OVNGmix)成功制备,该复合粒子的平均粒径为50~100nm,并且具有良好的稳定性。光热性能测试结果表明,复合粒子的光热转换效率达到50.54%,说明经修饰的金纳米星具有优异的光热转换能力。     

Bioinspired Aerogel with Vertically Ordered Channels and Low Water Evaporation Enthalpy for High-Efficiency Salt-Rejecting Solar Seawater Desalination and Wastewater Purification

Solar energy-driven water evaporation is a promising sustainable strategy to purify seawater and contaminated water. However, developing solar evaporators with high water evaporation rates and excellent salt resistance still faces a great challenge. Herein, inspired by the long-range ordered structure and water transportation capability of lotus stem, a biomimetic aerogel with vertically ordered channels and low water evaporation enthalpy for high-efficiency solar energy-driven salt-resistant seawater desalination and wastewater purification is developed. The biomimetic aerogel consists of ultralong hydroxyapatite nanowires as heat-insulating skeletons, polydopamine-modified MXene as a photothermal material with broadband sunlight absorption and high photothermal conversion efficiency, polyacrylamide, and polyvinyl alcohol as reagents to lower the water evaporation enthalpy and as glues to enhance the mechanical performance. The honeycomb porous structure, unidirectionally aligned microchannels, and nanowire/nanosheet/polymer pore wall endow the biomimetic aerogel with excellent mechanical properties, rapid water transportation, and excellent solar water evaporation performance. The biomimetic aerogel exhibits a high water evaporation rate (2.62 kg m⁻² h⁻¹) and energy efficiency (93.6%) under one sun irradiation. The superior salt-rejecting ability of the designed water evaporator enables stable and continuous seawater desalination, which is promising for application in water purification to mitigate the global water crisis.     

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.

     

Synergistic Dual-Mechanism Localized Heat Channeling and Spectrum-Tailored Liquid Metal Hydrogels for Efficient Solar Water Evaporation and Desalination

Photothermal hydrogels featuring broadband light absorption abilities and highly hydrated networks provide an appealing mass-energy transfer platform for water evaporation by using solar energy. However, the targeted delivery of solar heat energy to power the water evaporation process remains challenging. Herein, enlightened by metal-phenolic coordination chemistry and camouflaged architecture, photothermal hydrogels with dual-mechanism vaporization structure are tactfully designed via a rational interfacial engineering and integration strategy to enable near-µm heat confinement and highly efficient light-to-heat conversion ability. The spectrum-tailored liquid metal droplet (LMGAs-Fe^III) and optimized carbon-wrapped silver nanowire sponge (Ag@C₇₅₀) are integrally built as photothermal promotors/channels and jointly embedded into a highly hydratable poly(vinyl alcohol) hydrogel, denoted as PALGH, to synergistically boost water molecule activation and interfacial vaporization behavior by triggering robust photothermal performance. As a result, under one sun irradiation, the all-embracing PALGH hydrogel evaporation system achieves a brine evaporation rate to a high level of 3.47 kg m⁻² h⁻¹, and >19 L m⁻² clean water of PALGH is ideally delivered daily when purifying natural seawater. This work offers not only a rational design principle to create sophisticated photothermal materials but also replenishes insight into solar heat generation and water transportation in a cross-media system.