Photothermal Performance Research Articles

PlanarChiral Charge-Transfer Cyclophanes: Convenient Synthesis, Circularly Polarized Light-Responsive Photothermal Conversion and Supramolecular Chiral Assembly.

We report herein a series of macrocycles in which the densely π-stacked charge-transfer (CT) donor/acceptor with naphthalenediimides (NDIs) or perylene diimide (PDI) as acceptor moiety pairing various donor moieties are locked by covalent bond. The X-ray crystallography of C8BDT-NDI reveals a short intramolecular π-stacking distance around 3.4 Å and the existence of intermolecular donor/acceptor π-stacking (3.7 Å). The intramolecular CT is highly dependent on the electron-donating ability of donor moiety and replacing carbazole (C8KZ) with benzo[1,2-b:4,5-b']dithiophene (C8BDT) or dihydroindolo[3,2-b]indole (C8DN) redshift CT absorption into NIR region. Notably, both C8BDT-NDI and C8DN-NDI demonstrate excellent photothermal performance, which is a result of the active non-radiative pathways. Interestingly, the different molecular symmetry between donor and acceptor moiety endows C8BDT-NDI and C8DN-NDI with intrinsic planar chirality. The enantiomeric C8BDT-NDI shows chiral selectivity for incident light, i.e., when irradiated by left-circularly polarized light, (R)-C8BDT-NDI is more sensitive and a higher maximum stable temperature is achieved. While, enantiomeric C8DN-NDI pack with different orientations forming M- and P-handedness helix, respectively, demonstrating molecular planar chirality being transferred and amplified through molecularassembly. These results provide insight into the intramolecular charge transfer in enforced D/A π-stacks in which CT interactions and planar chirality would be engineered through structural control.

Planar Chiral Charge‐Transfer Cyclophanes: Convenient Synthesis, Circularly Polarized Light‐Responsive Photothermal Conversion and Supramolecular Chiral Assembly

We report herein a series of macrocycles in which the densely π‐stacked charge‐transfer (CT) donor/acceptor with naphthalenediimides (NDIs) or perylene diimide (PDI) as acceptor moiety pairing various donor moieties are locked by covalent bond. The X‐ray crystallography of C8BDT‐NDI reveals a short intramolecular π‐stacking distance around 3.4 Å and the existence of intermolecular donor/acceptor π‐stacking (3.7 Å). The intramolecular CT is highly dependent on the electron‐donating ability of donor moiety and replacing carbazole (C8KZ) with benzo[1,2‐b:4,5‐b']dithiophene (C8BDT) or dihydroindolo[3,2‐b]indole (C8DN) redshift CT absorption into NIR region. Notably, both C8BDT‐NDI and C8DN‐NDI demonstrate excellent photothermal performance, which is a result of the active non‐radiative pathways. Interestingly, the different molecular symmetry between donor and acceptor moiety endows C8BDT‐NDI and C8DN‐NDI with intrinsic planar chirality. The enantiomeric C8BDT‐NDI shows chiral selectivity for incident light, i.e., when irradiated by left‐circularly polarized light, (R)‐C8BDT‐NDI is more sensitive and a higher maximum stable temperature is achieved. While, enantiomeric C8DN‐NDI pack with different orientations forming M‐ and P‐handedness helix, respectively, demonstrating molecular planar chirality being transferred and amplified through molecular assembly. These results provide insight into the intramolecular charge transfer in enforced D/A π‐stacks in which CT interactions and planar chirality would be engineered through structural control.

Bifunctional Photothermal Evaporator Based on an MXene/Fe-MOF Collaborative Effect toward Efficient Solar Steam Generation and Simultaneous VOC Removal.

Solar-driven interfacial water evaporation has become one of the most promising approaches to effectively harvesting freshwater, yet the fabrication of high-performance and multifunctional solar interfacial evaporators (SIEs) still remains a huge challenge to date. In this study, a multifunctional MXene and Fe-MOF@cellulose acetate/polyvinylpyrrolidone (MXM@CP) SIE was prepared via a facile "electrospinning and suction filtration deposition" coupling strategy. Thanks to the incorporation of MXene, MXM@CP displayed excellent photothermal conversion performance. Together with the fast water transport channel provided by the porous cellulose acetate electrospinning substrate, a remarkable solar-driven water evaporation property was achieved for MXM@CP, showing a higher water evaporation rate of 1.1 kg m-2 h-1 under one sun irradiation. Moreover, the resultant composite film also exhibited excellent Fenton catalytic activity to effectively degrade volatile organic compounds (VOCs) due to the synergistic effect of the MXene and Fe-based MOF (Fe-MOF). Particularly, a relatively higher degradation rate of 82.8% was acquired for the resulting evaporator toward the benzene contaminant. These results provide new insights into the construction of high-performance and multifunctional SIEs toward clean freshwater collection from the VOC-contaminated water system.

Extremely Fast Wicking Self‐Layered Interpenetrating Network Hydrogel for Rapid All Day Collection of Atmospheric Water

AbstractHygroscopic salt hydrogel photothermal composites and related technology are a promising pathway for water harvesting. However, due to the overly cumbersome preparation process, the distribution of the surface photothermal layer is difficult to control and the photothermal efficiency is low. In this paper, a method is proposed to greatly simplify the preparation process of photothermal layer hydrogels and improve their atmospheric water harvesting performance by constructing temperature‐sensitive interpenetrating networks. Due to the decomposition of some reversible hydrated structures in the network during heating and warming, carbon nanotubes move autonomously to form a layered structure with a photothermal effect on the upper surface, which can return to its original state after cooling and remain stable at room temperature or under solar illumination. Compared with hydrogels with general layered structure or overall distribution of photothermal materials, agar/GG/PAM/CNT hydrogel has faster moisture adsorption efficiency and higher desorption efficiency, and during the 24 h continuous sorption–desorption cycle is capable of achieving high water yield of 2.57 Lwater kgsorbents−1 day−1, superior to most recent hydrogel adsorbents. Simplifying the preparation process while maintaining high efficiency, while greatly improving photothermal performance, paves the way for cost‐effective mass production applications for a wide range of hygroscopic salt‐hydrogel photothermal composites.

Supramolecular photothermal agents mediated by black hole hosts

High-performance organic photothermal agents (PTAs) hinges primarily on manipulating non-radiative decay processes, which typically necessitates intricate and time-intensive molecular engineering. The main challenge is how to bring dye and quencher into close molecular contact at a sub-nanometer distance for effective quenching. A host-guest strategy is presented to fabricate supramolecular PTAs by non-radiative electron transfer. Through strong complexation of dye with a “black hole host”, quaternary-ammonium modified calix[4]arene tetraoctyloxy ether (QC4A-8C), photothermal performances of ten distinct dyes were optimized to an unprecedented degree. The potential of supramolecular PTAs in biological application was evaluated photothermal therapy in vitro and in vivo using zinc tetrasulfonate phthalocyanine@QC4A-8C. This study provides insights into leveraging existing dyes to augment photothermal effects through electron transfer, offering a streamlined pathway for the development of safe and efficient supramolecular PTAs.

Fabrication of Low-Cost Porous Carbon Polypropylene Composite Sheets with High Photothermal Conversion Performance for Solar Steam Generation.

The development of absorber materials with strong light absorption properties and low-cost fabrication processes is highly significant for the application of photothermal conversion technology. In this work, a mixed powder consisting of NaCl, polypropylene (PP), and scale-like carbon flakes was ultrasonically pressed into sheets, and the NaCl was then removed by salt dissolution to obtain porous carbon polypropylene composite sheets (P-CPCS). This process is simple, green, and suitable for the low-cost, large-area fabrication of P-CPCS. P-CPCS has a well-distributed porous structure containing internal and external connected water paths. Under the dual effects of the carbon flakes and porous structure, P-CPCS shows excellent photothermal conversion performance in a broad wavelength range. P-CPCS-40 achieves a high temperature of 128 °C and a rapid heating rate of 12.4 °C/s under laser irradiation (808 nm wavelength, 1.2 W/cm2 power). When utilized for solar steam generation under 1 sun irradiation, P-CPCS-40 achieves 98.2% evaporation efficiency and a 1.81 kg m-2 h-1 evaporation rate. This performance means that P-CPCS-40 outperforms most other previously reported absorbers in terms of evaporation efficiency. The combination of carbon flakes, which provide a photothermal effect, and a porous polymer structure, which provides light-capturing properties, opens up a new strategy for desalination, sewage treatment, and other related fields.

Antibacterial and antioxidant supramolecular nanocomposite hydrogel dressings with angiogenesis and photo-thermal effect for multidrug‐resistant bacterial infected wound healing

Antioxidant, antibacterial and removable supramolecular nanocomposite hydrogel dressings with self-healing and tissue adhesiveness is highly anticipated for bacterial infected skin wound healing. A series of supramolecular nanocomposite hydrogels via quadruple hydrogen bond and coordination bonds (catechol-Cu) was developed based on ureidopyrimidinone-modified poly(glycerol sebacate)–co-poly(ethylene glycol)-g-catechol (PEGSDU) and mesoporous copper sulfide nanoparticle (CuS NPs) as antioxidative, antibacterial, removable and tissue-adhesive dressing to treat the MRSA-infected wound. The hydrogels exhibited good self-healing, free radical scavenging, photothermal sterilization performance, adhesiveness, and temperature-sensitive removability. In addition, the Cu2+ was able to be slowly released from the hydrogel, which can promote the proliferation and migration of fibroblasts. Hydrogels containing CuS NPs showed better wound repair efficiency than commercial TegadermTM films and hydrogels without CuS NPs in MRSA-infected skin wound, which was attributed to the good antibacterial property, improved collagen deposition, reduced inflammatory response, and improved new vessels formation, thereby significantly promoting the repair of wounds. In summary, this antioxidative and antibacterial supramolecular nanocomposite hydrogel dressing provide a new type of multi-functional dressing for the treatment of infected skin wounds.

Anti/de-icing superhydrophobic coating with durability and self-healing by infiltrating photothermal self-stratifying organic layers into plasma-sprayed porous Al2O3–13%TiO2 underlayer

Superhydrophobic coatings simultaneously exhibiting high substrate binding, mechanical durability and self-healing properties are of great significance for anti/de-icing applications. In this study, we fabricated a high substrate binding and mechanical durability anti/de-icing superhydrophobic coatings (SL-AP/SPS-SiO2) with self-healing performance by spray-coating a photothermal self-healing organic layers (AP/SPS-SiO2) plasma-sprayed porous Al2O3–13%TiO2 underlayer (SL), the resulting soft-hard interlocking structure significantly increased the adhesion strength of the coating to 16.7 ± 0.36 MPa while reducing the ice adhesion strength to 46.5 ± 3.0 kPa. In the as-obtained organic layers, self-stratifying acrylic resin (AR)/20%polymethylsiloxane (PDMS) (AP), not only enhanced the bonding strength with the underlayer but also imparted photothermal self-healing capability to the coating through the action of the photothermal agent (SPS-SiO2). And sodium alginate (SA) guided the self-oxidative polymerization of dopamine (DA) and its deposition on hydrophilic SiO2 to form a π-π stacked fiber structure photothermal agent (SPS), after hydrophobic SiO2 modification increased the coating's roughness and photothermal performance. Remarkably, the coating achieved a contact angle of up to 158.4 ± 0.89° and a rolling angle of 3.5 ± 0.89°, maintaining its superhydrophobic properties even after exposure to acid-base immersion and mechanical abrasion. Furthermore, the coating exhibited self-healing capabilities in superhydrophobicity against O2 plasma etching, with a contact angle recovery rate of up to 98.9% after undergoing 10 cycles of O2 plasma etching and light exposure. Enhancing mechanical and chemical stability with self-healing capabilities is beneficial for extending the lifespan of superhydrophobic coatings used in anti-/de-icing applications.

MXene and cellulose nanofibers reinforced hydrogel with high strength and photothermal self-healing performances for marine antifouling

Biological fouling is a considerable threat to the marine industry because attached microcontaminants and microorganisms inflict serious damage on marine installations and aquacultures. Although there has been tremendous effort in researching marine antifouling, it is yet challenging to develop a long-term and consistent antifouling strategy and materials. Here, polyhexamethylene-biguanide (PHMB) and MXene are introduced into the carboxylated cellulose nanofibers (CNF) reinforced polyvinyl alcohol (PVA) hydrogel to obtain a self-healing and ultra-high toughness antifouling hydrogel. The as-prepared double network (DN) hydrogels have extremely high toughness (16,050 kJ/m3), superior anti-protein adhesion (100 %) and anti-algal adhesion (100 %), exceptional antibacterial activity (99.97 %), and remarkable photothermal self-healing capability. Furthermore, the DN hydrogel provide outstanding antifouling performance for at least six months in the actual marine field. This work provides an effective and feasible strategy to prevent marine biofouling and also initiates new approaches to the application of hydrogel.

Synergetic integration of photothermal and self-cleaning features in a composite phase change material based on layered double hydroxides and polypyrrole

Composite phase change materials (PCMs) with photothermal functionality play a crucial role in efficiently storing and utilizing solar energy. However, the challenge of effectively removing of contaminants on photothermal conversion coatings has long puzzled researchers. In this study, we propose a novel approach to enhancing both photothermal conversion performance and self-cleaning properties of wood-based composite phase change materials, ultimately facilitating the sustainable and effective utilization of solar energy. The method utilized metal-organic frameworks (MOFs) as a precursor to form rough layered double hydroxides (LDH) on the wood surface through hydrolysis-induced exchange. Subsequently, polypyrrole (PPy) was deposited through vapor phase onto the LDH, and paraffin wax (PW) is utilized as the phase change material to prepare a novel composite phase change material. This modified wood structure facilitates leak-proof PW encapsulation and effective heat storage (167.6 J/g). PPy acts as a proficient photothermal converter and improves the composite material's heat transfer efficiency by establishing thermal conduction pathways, resulting in an 87.4 % enhancement in thermal conductivity compared to pure PW. The rough surface of LDH promotes multiple light reflections and scattering within the material, leading to increased light absorption by the PPy coating and achieving a photothermal conversion efficiency of up to 96.4 %. Furthermore, the high roughness of the LDH layer combined with the low surface energy of PW imparts superhydrophobic self-cleaning properties to the material, ensuring sustained effectiveness of the photothermal conversion coating over time. This research presents a viable approach for maintaining the cleanliness and efficiency of solar energy systems.

A wearable cotton fiber-based supercapacitor electrode material with outstanding stability and photothermal performance utilizing AgNWs, NiCoAl-LDH, and PPy-NWs.

Designing cotton fiber (CF) based flexible electrode materials with both electrochemical energy storage and structural stability is crucial for the utilization of flexible supercapacitors in wearable devices. Nevertheless, the electrochemical properties of such materials are often constrained by suboptimal ion diffusion, a limited electroactive surface area, and inadequate structural integrity. Herein, Silver nanowires (AgNWs), NiCoAl hydrotalcite (NCA-LDH), and polypyrrole nanowires (PPy-NWs) are employed to construct a CF-based electrode material (PNHAS/CF) with high stability through a layer-by-layer self-assembly method. The PNHAS/CF with a high capacitance of 1207.58 mF cm-2 at 5mAcm-2 due to the faster electronic transmission paths of AgNWs and PPy-NWs, and the high specific capacitance of NCA-LDHs. The NCA-LDH stabilizes the PPy-NWs molecular chain, and the PPy-NWs winding structure can further enhance the PNHAS/CF's structural stability and prevent the AgNWs network from being destroyed, which guarantees the exceptional 87.5% capacitance retention after 2000cycles. The constructed symmetrical supercapacitor shows an energy density of 36.28 μWh cm-2 at 0.31mWcm-2 power density. The PNHAS/CF exhibits superb solar spectral absorptivity (~94.8%) and outstanding solar heating performance. Surprisingly, the fiber-based flexible electrode material and the assembled supercapacitor are expected to find applications in wearable intelligent electronics.

Cation induced electrostatic adsorption driven self-assembly sandwich-like α-MnO2/MXene for efficient self-heating photothermal synergistic catalytic decomposition of carcinogenic gaseous formaldehyde

Realizing self-assembly between different nanoparticles is an important strategy for constructing novel nanostructures or excellent functional composites. Formaldehyde is the primary gaseous pollutant in indoor air, and achieving its ambient temperature decomposition is of great significance for improving indoor air quality. This research reports an electrostatic adsorption driven self-assembly strategy, constructing a sandwich structure α-MnO2/MXene for self-heating photothermal synergistic catalytic decomposition of formaldehyde. The self-assembly process and electrostatic adsorption driven mechanism were detailed. A comparative study was conducted on the performance and mechanisms of the self-assembled sandwich structure and mechanically mixed α-MnO2/MXene in the self-heating photothermal catalytic decomposition of formaldehyde. The sandwich structure α-MnO2/MXene with built-in electric field and Schottky barrier exhibited excellent self-heating photothermal catalytic activity for formaldehyde decomposition, realizing the 100% mineralization of formaldehyde under simulated solar-light irradiation at room temperature; even with the irradiation of visible light, the sandwich structure α-MnO2/MXene can still maintain 82.6% HCHO conversion. Furthermore, we elucidated the self-heating photothermal catalytic mechanism, shedding light on the distinct roles and contributions of photocatalysis and thermal catalysis. It was found that the photothermal catalytic mechanism of the sandwich structure α-MnO2/MXene-S composite involved a thermally assisted photocatalytic process. The advantages of the self-assembled sandwich structure and its mechanism for enhancing photothermal performance were fully revealed. This study reports an effective strategy for electrostatic adsorption self-assembly, offering a fresh perspective on developing non-noble metal catalysts for ambient-temperature formaldehyde decomposition

Ag-S coordination strategy for high recovery driving stress in recyclable shape memory polymers

To address the issue of low strength and recovery stress in recyclable shape memory polymer (SMP) materials with dynamic covalent bonds in practical applications, we propose a method based on Ag-S coordination interactions to improve dynamic covalent bonds, thereby preparing recyclable SMP with high recovery stress and large recovery strain. The introduction of in situ reduced silver nanoparticles (AgNPs) in the SMP system play multiple roles, serving as additional physical crosslinking points at the microscale and coordinating with disulfide bonds in the system to construct a multi-level dynamic network structure. This endows the material with exceptional mechanical properties (tensile strength of 25.93 MPa and fracture strain of 1466.83 %) and recovery driving stress (5.59 MPa), while maintaining more than 99 % shape recovery and fixity rate. Furthermore, due to the outstanding photothermal performance of AgNPs, the composite material has acquired remote photothermal driving capabilities. The proposed Ag-S coordination enhancement offers a new approach for SMP materials that achieve both large actuation distance and high recovery stress, holding significant potential for applications in soft robotics and actuators.

Antisense oligonucleotide facilitate the photothermal therapy of Mxene-based nanoplatform for drug-resistant breast cancer

Breast cancer has become the most common form of cancer worldwide. Chemotherapy failure, primarily due to drug resistance, necessitates the development of new therapeutic strategies. In this study, ultrathin Ti3C2 nanosheets are utilized as photothermal agents and nanocarriers. We developed a multifunctional Ti3C2-based nanoplatform (214.7 nm) through layer-by-layer absorption of HSP90 antisense oligonucleotide (ASO) and doxorubicin (DOX), with surface modification using hyaluronic acid (HA). In a simulated acidic tumor microenvironment in vitro, 90 % of the drug was released within 36 hours. Additionally, Under 808 nm irradiation (2.0 W/cm²), MCF-7/ADM cell viability assays revealed the following results: HA-Ti3C2 (57 %), HA-Ti3C2@ASO (HT@A) (41 %), and HA-Ti3C2@ASO/DOX (HT@AD) (26 %), which shown the synergistic inhibitory effects of this multifunctional nanoplatform. Herein, this nanosystem exhibits enhanced biocompatibility, superior photothermal performance, and stimuli-responsive drug release behavior, making it a promising candidate for effective inhibition of cancer cell proliferation and migration.

Photothermal/magnetothermal coupled polyphenylene sulfide composite membranes for ultra-efficient and continuous seawater desalination

As the population continues to expand and industrialization gathers pace, the rate at which freshwater resources are dwindling is alarming. Solar desalination technology has shown encouraging results in generating clean water. However, solar-driven interfacial evaporation technology still faces a series of major challenges, specifically manifested in its low efficiency, poor chemical stability, and the tendency for salt crystallization to accumulate on the evaporation surface during operation. In this work, we proposed a novel magneto/photo-thermal coupled evaporator based on polyphenylene sulfide (PPS) fibrous membrane, which showed excellent high temperature and corrosion resistance. This non-contact responsive interfacial evaporator exhibited outstanding photothermal and magnetothermal conversion performance properties. Under one solar illumination, the evaporation rate of this evaporator could reach 1.52 kg m−2 h−1, corresponding to an evaporation efficiency of 91.84 %. In addition, under a magnetic field power of 2 kW m−2, the evaporator could achieve a remarkable evaporation rate of 4.2 kg m−2 h−1 under one solar illumination, with an evaporation efficiency of up to 93.77 %. Moreover, it also exhibited superb salt resistance, great mechanical properties, long-term operational stability, and outstanding dye purification property. Furthermore, by integrating the thermoelectric generator with the evaporator and utilizing the waste heat from the evaporation process to generate electricity, the efficiency of energy utilization has been improved. The interfacial evaporator opens up vast prospects for efficient and rapid clean water production, demonstrating significant potential and advantages.

Poly-dopamine coated-cellulose/chitosan hybrid carbon aerogel composite phase change materials with efficient photothermal conversion and storage

Solar energy, being both low-cost and renewable, is a viable alternative for thermal storage and can help mitigate the energy crisis. Efficient conversion and storage for solar energy can significantly enhance energy utilization. Phase change materials (PCMs), such as paraffin (PW), are capable of harvesting and converting solar energy into thermal energy, thus playing a crucial role in solar energy utilization. However, PW faces challenges, such as solid–liquid leakage and low photothermal conversion efficiency, which hinder its applications in solar energy storage. In this study, we proposed the construction of a robust poly-dopamine (PDA)/chitosan (CS)/cellulose nanofibers (CNF) carbon aerogel with enhanced photothermal performance. This is achieved by incorporating PDA, known for its excellent light absorption properties, and cross-linking it with low-cost biomass CS and CNF via a Schiff base reaction. The resulting novel composite PCMs exhibit high photothermal conversion efficiency and shape stability by encapsulating PW within the PDA/CS/CNF carbon aerogel. Our findings demonstrate that the composite PCMs have a high melting energy-storage capacity of 209.57 J/g. Notably, the introduction of PDA significantly improved the photothermal conversion efficiency by 94.9 %. These results suggest that composite PCMs hold great potential for applications in photothermal energy conversion and storage.

GSH responsive AuNRs@TFF nanotheranostic for NIR-II photoacoustic imaging-guided CDT/PTT synergistic cancer therapy

Gold nanorods (AuNRs) are important photothermal therapeutic agents; however, a single therapy does not achieve satisfactory outcomes, and the synthesis process often leads to the adsorption of cetyltrimethylammonium bromide on the surface of AuNRs, which reduces its biocompatibility. Natural polyphenols are abundant in natural plants and have good biocompatibility. The metal-polyphenol network is formed by the coordination of metal ions and polyphenols, which has good drug loading, surface adhesion, and biocompatibility. In this study, the metal-polyphenol network structure formed by a transition metal (iron) and natural polyphenol tannic acid was used to modify the surface of gold nanorods (AuNRs@TF). Additionally, the surfaces of AuNRs were modified using the targeted functional molecule mercapto folic acid (AuNRs@TFF). The constructed composite nanomaterials AuNRs@TFF has good biocompatibility and tumor targeting ability. Tannic acid‑iron degrades in the tumor microenvironment and releases iron ions that catalyze the Fenton reaction, thereby facilitating chemodynamic therapy. The good photo-thermal ability of AuNRs generate good photoacoustic signals to facilitate photoacoustic imaging mediation and enhances photothermal and chemodynamic therapy performance. This study expands on the application of AuNRs in the field of nanomedicine. The simple and effective design of AuNRs@TFF provides a strategy for the development of synergistic therapeutic agents for photothermal therapy and chemodynamic therapy.

Construction of aptamers-modified plasmonic GO/urchin-like Au nanoparticles with enhanced photothermal performance and their efficient capture and elimination of Staphylococcus aureus

Here, aptamers-modified graphene oxide/urchin-like Au nanoparticles (Apt-GUANPs) were developed for efficient capture and photothermal therapy (PTT) of Staphylococcus aureus (S. aureus). Specifically, anisotropic UANPs were first prepared, and the excellent photothermal property was related to the localized surface plasmon resonance (LSPR) in the near infrared (NIR) region caused by sharp branching. Then GO, which was used to enhance the photothermal effect, was added and assembled into GUANPs by electrostatic action. Infrared images showed that GUANPs exhibited a stronger photothermal effect than UANPs. Under the irradiation of 808 nm laser, the photothermal conversion efficiency (η) of GUANPs was as high as 40.5 %, which was attributed to the enhanced optical response of GUANPs at 808 nm and the strong plasmonic coupling effect between tightly packed UANPs loaded on GO surfaces. Aptamers were modified on the surfaces of GUANPs for specific capture of S. aureus, with the capture efficiency of up to 72 %. Utilizing the specific capture ability of aptamers and the excellent photothermal property of GUANPs, Apt-GUANPs exhibited the strong photothermal killing ability against S. aureus. Therefore, Apt-GUANPs will be a promising and efficient photothermal agent, and will have a great application prospect in the treatment of bacterial infections in the future.

Efficiently all-weather anti-icing and de-icing coatings enabled by polyaniline microcapsules encapsulated phase change materials

Photothermal superhydrophobic coatings are one of the most promising anti-icing/de-icing materials. However, the intermittence of light energy limits the application of photothermal energy conversion technologies when continuous de-icing is required. Herein, an innovative solution for the integration of photothermal effect and phase change thermal storage was proposed. In this work, an efficient anti-icing/de-icing coating was successfully fabricated based on multifunctional polyaniline microcapsule encapsulating butyl stearate (BS). Benefiting from the heat storage capacity of BS in the microcapsule, the coating could achieve all-weather anti-icing capability. Under the condition of −20 °C, the freezing time of water droplets on the coating with only 10 wt% microcapsules was delayed by about 12.6 times compared to the blank coating. At the same time, under simulated dark conditions, the freezing time of water droplets could be delayed by about 14.1 times. Moreover, owing to the thermal conductivity and high solar energy exploitation, polyaniline endowed the coating with outstanding photothermal de-icing performance, presenting the superiority of outdoor applications. Under NIR (200 mW/cm2) illumination, the melting time of water droplets was reduced to 18 s, which was nearly 10 times faster than that on the blank coating. Moreover, the polyaniline microcapsules also possessed outstanding anticorrosion property, which was particularly attractive for mental coating applications. The combined properties of this all-weather anti-icing and de-icing coating could render it a promising contender for challenging outdoor applications.

Principle of vanadium doping-induced MoS2 homojunction effect and mechanism analysis of antibacterial process under near-infrared light

MoS2 exhibits unique physical and chemical properties in its 1 T and 2H phases. Each phase has its inherent advantages and limitations. Although several biochemical properties of MoS2 have been extensively reported, the specific impacts of these phases on photothermal and antibacterial performance, the feasibility of integrating the unique advantages of both phases and the underlying dominant bactericidal mechanisms are still largely unexplored. In this work, the electronic-structural relationships of 1 T- and 2H-MoS2 were first simulated using density functional theory (DFT), which provided unique insights into how these phases affect performance. Based on these insights, a solid-state coupling interface and built-in electric field were designed between the two phases, and a 1 T/2H MoS2 homojunction was synthesized using the hydrothermal method, achieving a higher carrier separation efficiency and exhibiting excellent photothermal and antibacterial properties. Subsequently, further attempts were made to adjust the electronic structure by doping vanadium atoms. This doping not only introduces additional electrons to facilitate electron transfer but also further enhances the antibacterial capability by creating surface defects that increase the number of active sites. Finally, the synergistic antibacterial mechanism of this system was thoroughly investigated through detailed experiments and DFT theoretical analysis. The design of the homojunction, the introduction of defects, and the incorporation of heteroatoms were discussed in this paper, which pave the way for the rational design strategy of advanced two-dimensional materials and can be extended to other polycrystalline materials.