Photothermal Performance Research Articles

Light-responsive biowaste-derived and bio-inspired textiles: Dancing between bio-friendliness and antibacterial functionality

Functional antibacterial textiles fabricated from a hybrid of organic waste-derived and bio-inspired materials offer sustainable solutions for preventing microbial infections. In this work, we developed a novel antibacterial textile created through the valorization of spent coffee grounds (SCG). Electrospinning and electrospraying techniques were employed to integrate the biowaste within a polymeric nanofiber matrix, ensuring uniform particle distribution and providing structural support for enhanced applicability. Modification with polydopamine (PDA) significantly enhanced the textile's photothermal performance. Specific attention was paid to understanding the relation between temperature change and key variables, including the surrounding liquid volume, textile layer stacking, and applied laser power. Developed platforms demonstrated excellent photothermal stability. While the SCG-based textile demonstrated exceptional biocompatibility, the PDA-modified textile effectively eradicated Staphylococcus aureus (S. aureus) under near-infrared (NIR) irradiation. The developed textiles in our work demonstrate a dynamic balance between biocompatibility and on-demand antibacterial functionality, offering adaptable solutions in accordance with the desired application.

Fabrication of a novel macrophage-targeted biomimetic delivery composite hydrogel with multiple-sensitive properties for tri-modal combination therapy of rheumatoid arthritis

In this study, a porous polydopamine (PDA) nanoparticle-decorated β-glucan microcapsules (GMs) nanoplatform (PDA/GMs) were developed with macrophage-targeted biomimetic features and a carriers-within-carriers structure. Indocyanine green (ICG) and catalase (CAT) were subsequently co-encapsulated within the PDA/GMs to create a multifunctional nanotherapeutic agent, termed CIPGs. Furthermore, CIPGs and sinomenine (SIN) were co-loaded within a thermo-sensitive hydrogel to design an injectable delivery system, termed CIPG/SH, with potential for multi-modal therapy of rheumatoid arthritis (RA). Photothermal studies indicated that the CIPGs hold excellent photothermal conversion ability and thermal stability, as they combined the photothermal performance of both PDA and ICG. Meanwhile, the CIPGs displayed favorable oxygen self-supplying and photodynamic performance. The CIPGs showed near-infrared (NIR)-induced phototoxicity, effectively inhibiting macrophage proliferation and displaying remarkable antibacterial activity. In vitro drug release from the prepared CIPG/SH showed a controlled release pattern. Animal experiments conducted on an RA mice model confirmed that the formulated CIPG/SH exhibited significant therapeutic effects. By integrating the biological advantages, photothermal/photodynamic performance of the CIPGs, and controlled drug release performance of the thermo-sensitive hydrogels in a single delivery system, the prepared injectable CIPG/SH represents a novel versatile delivery system with great potential for multi-modal combination targeting therapy in RA.

Green hydrogen and acetaldehyde production via photo-induced thermal dehydrogenation of bioethanol over a highly dispersed CuS/ TiO2 catalyst

The emergence of global warming issues has triggered the interest in producing carbon-neutral energy sources and fossil-based chemicals from affordable and renewable feedstocks (e.g., bio-ethanol). Herein, the synthesis of highly dispersed CuS/TiO2 photothermal catalysts is reported for simultaneously converting ethanol into hydrogen and acetaldehyde under simulated sunlight. The catalyst achieved a hydrogen evolution rate of 51.61 mmol g−1 h−1 and an acetaldehyde production rate of 48.63 mmol g−1 h−1, with a maximal acetaldehyde selectivity of 97% among carbon-containing products. Compared to pristine TiO2, the introduction of plasmonic CuS largely extended the light adsorption range and enhanced the photothermal performance, whilst the formation of heterojunction structure improved the charge transfer and separation efficiency. The density functional theory calculation results demonstrate that CuS/TiO2 composite interfaces could significantly lower the activation energy of ethanol dehydrogenation reaction and improve hydrogen evolution reaction ability. This study provides deep insight into understanding and optimizing hot carrier dynamics in photothermal catalytic systems.

Graphene Oxide/Black Phosphorus Functionalized Collagen Scaffolds with Enhanced Near-Infrared Controlled In Situ Biomineralization for Promoting Infectious Bone Defect Repair through PI3K/Akt Pathway.

Infectious bone defects resulting from surgery, infection, or trauma are a prevalent clinical issue. Current treatments commonly used include systemic antibiotics and autografts or allografts. Nevertheless, therapies come with various disadvantages, including multidrug-resistant bacteria, complications arising from the donor site, and immune rejection, which makes artificial implants desirable. However, artificial implants can fail due to bacterial infections and inadequate bone fusion after implantation. Thus, the development of multifunctional bone substitutes that are biocompatible, antibacterial, osteoconductive, and osteoinductive would be of great clinical importance. This study designs and prepares 2D graphene oxide (GO) and black phosphorus (BP) reinforced porous collagen (Col) scaffolds as a viable strategy for treating infectious bone defects. The fabricated Col-GO@BP scaffold exhibited an efficient photothermal antibacterial effect under near-infrared (NIR) irradiation. A further benefit of the NIR-controlled degradation of BP was to promote biomineralization by phosphorus-driven and calcium-extracted phosphorus in situ. The abundant functional groups in GO could synergistically capture the ions and enhance the in situ biomineralization. The Col-GO@BP scaffold facilitated osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSC) by leveraging its mild photothermal effect and biomineralization process, which upregulated heat shock proteins (HSPs) and activated PI3K/Akt pathways. Additionally, systematic in vivo experiments demonstrated that the Col-GO@BP scaffold obviously promotes infectious bone repair through admirable photothermal antibacterial performance and enhanced vascularization. As a result of this study, we provide new insights into the photothermal activity of GO@BP nanosheets, their degradation, and a new biological application for them.

Generation of oxygen vacancies in CuO/TiO2 heterojunction induced by diatomite for highly efficient UV–Vis-IR driven photothermal catalytic oxidation of HCHO

Photothermal catalytic oxidation is a promising and sustainable method for the degradation of indoor formaldehyde (HCHO). However, the excessively high surface temperature of existing photothermal catalysts during catalysis hinders the effective adsorption and degradation of formaldehyde under static conditions. Catalyst loading and oxygen vacancies (OVs) modulation are commonly employed strategies to reduce the photothermal catalytic temperature and enhance the efficiency of photothermal catalytic oxidation. In this work, a p-n type CuO/TiO2 heterojunction is successfully loaded onto diatomite using a wet precipitation method. Under the irradiation of a 300W xenon lamp, the prepared composite material achieved a 100% removal rate of HCHO within 2 h, with a 98% conversion rate to CO2, surpassing the performance of both individual photocatalysts and thermocatalysts. Additionally, by adjusting conditions such as light irradiation and temperature, we have demonstrated that this material exhibits synergistic photothermal catalytic properties. Based on HRTEM, XPS, Raman, and EPR analyses, the introduction of diatomite as a catalyst support was shown to effectively increase the number of OVs. Experimental results, along with O2-TPD, photoelectrochemical characterization, and radical detection, demonstrate that the presence of OVs enhances the oxidative efficiency of both photocatalysis and thermocatalysis, as well as the UV–Vis-IR photothermal catalytic performance. The ternary composite material generates weak hydroxyl (•OH) and superoxide (•O2−) radical under high-temperature with dark conditions, indicating its catalytic oxidation activity under this condition. The increase in temperature and the expansion of the spectral range both enhance the generation of these radicals. In summary, this work demonstrates that the use of diatomite as a support increases the material's specific surface area and OVs content, thereby enhancing adsorption and photothermal catalysis. It elucidates the enhanced catalytic degradation mechanism of this mineral-based photothermal catalyst.

Phase change material composites based on 3D lignin-derived porous carbon prepared by in-situ activation for efficient solar-driven energy conversion and storage

Utilization of three-dimensional biomass-derived porous carbons can effectively address issues of easy leakage, low thermal conductivity, and weak photothermal conversion of phase change materials (PCMs). This enables the production of high-performance composites for solar-induced energy collection, conversion, and storage. In this study, hierarchical lignin-derived porous carbon (HLPC), microporous lignin-derived porous carbon (MILPC) and mesoporous lignin-derived porous carbon (MELPC) were prepared through high-temperature in-situ activation using lignosulphonate (LS) as a carbon precursor and CaCO3, KOH and ZnCO3 as activators. Carbon-based PCM composites with high performance were obtained by encapsulating paraffin wax (PW) in porous carbon supports. Results demonstrated that PW/HLPC exhibited comprehensive performance superior to other tested PW composites owing to its higher specific surface area (2,358 m2/g), larger pore volume (1.1 cm3/g) and well-interconnected framework structure. Additionally, PW/HLPC displayed relatively high latent heat (123.4 kJ/kg), photothermal conversion and storage efficiency (95 %), and photoelectric conversion performance (174.5 mV). Moreover, PW/HLPC also showed better leak-proof properties at 90 °C. The cycling stability and photothermal conversion performance of PW/HLPC were superior to those of the selected crude biochar-based PW composites. This study highlights the advantages of the prepared PW/HLPC for both the high-value utilization of lignin and its practical applications in solar-induced energy harvest, conversion, and storage.

Exploring the potential of nanoparticles-based polydopamine for effective treatment of refractory keratitis: Mild photothermal loop therapy

Keratitis is the leading cause of blindness worldwide. In refractory cases, it can even lead to eyeball enucleation. The critical challenges of refractory keratitis are the drug-resistant bacteria and bacterial biofilms formation. Therefore, we established an innovative therapeutic approach for keratitis based on mild photothermal loop (MPL) therapy. First, we analyzed the bactericidal effect of methicillin-resistant Staphylococcus aureus (MRSA) under various loops and temperature durations to determine the optimal condition. Then, RAN-seq was applied to explore the underlying mechanisms. Additionally, we formulated a dual-purpose polyvinyl alcohol-polydopamine (PDA/PVA) hydrogel system and explored its effects on the reactive oxygen species (ROS) scavenging capability, antibacterial properties, and anti-inflammatory properties in vitro, as well as its effect in vivo. The results indicated substantial bactericidal properties after exposure in four loops, each lasting 10 min at 45 °C. RNA-seq revealed the altered genes related to virulence and biofilm formation. In addition to good photothermal performance, the PDA/PVA system could effectively eliminate MRSA, reduce ROS, inhibit biofilm formation, and decrease inflammatory factors expression. Moreover, the in vivo results demonstrated the potential of MPL for bacterial keratitis. This study serves as the first attempt to use MPL therapy for refractory keratitis, offering a new approach for clinical practice.

Facile synthesis of Ti3C2Tx MXene nanosheets using aryl diazonium tetrafluoroborate for multiple applications

The development of an HF-free and environmentally benign method for etching the middle aluminum layer (Al) from the Ti3AlC2-MAX phase is a challenging task in titanium carbide (Ti3C2Tx) MXene synthesis. Herein, we designed a diazonium salt-based ultrasonic method to prepare MXene. We have explored 4-carboxy benzene diazonium tetrafluoroborate (4-CBDF) as a delaminating agent, which can dissolve the Al layer directly from the MAX phase. 4-carboxy benzene diazonium (4-CBD+) ion promotes the intercalation as well as exfoliation simultaneously during the etching of the MAX phase and directly results in Ti3C2Txnanosheets without undergoing any additional delamination process. Synthesized MXene nanosheets show excellent photothermal performance with a conversion efficiency of 59 %. This MXene-coated GC electrode exhibits the highest capacitance of 1133 F/g at a current density 1 A/g, which maintains a retention capacitance of 91% even after 10,000 GCD cycles. The present method provides a fundamental insight into the development of MXene-based next-generation photothermal materials and supercapacitors.

Rigid coordination environment induced MOFs to achieve an efficient photothermal conversion efficiency

A rigid coordination environment contributes significantly to stabilizing the framework structure of Metal-Organic Frameworks (MOFs) and reducing the spatial distance between functional ligands, thereby inducing charge transfer effects. In this context, achieving partial and complete coordination of TTF(py)4 in MOFs involves regulating the number and position of carboxylic acid substitutions in the ligand. Notably, TTFBDAT-Zn-MOF demonstrates a more rigid coordination environment compared to TTFBCAT-Zn-MOF. This enhanced coordination environment facilitates energy transfer between donor and acceptor units in MOFs, enabling efficient photothermal conversion performance under 808 nm excitation. The maximum temperature of TTFBDAT-Zn-MOF can reach 190 °C, while the maximum temperature of TTFBCAT-Zn-MOF can only reach 118 °C. Therefore, TTFBDAT-Zn-MOF with rigid structure has superior photothermal conversion performance.

Fe3O4/Au@SiO2 nanocomposites with recyclable and wide spectral photo-thermal conversion for a direct absorption solar collector

The Fe3O4-based photothermal materials have been widely applied for the recycling of heavy metal nanoparticles to avoid secondary pollution in the utilization of solar energy owing to excellent magnetic properties. However, the narrow absorption band of Fe3O4 or metal nanoparticles limits their capacity for solar energy harvesting. In this paper, a recyclable and wide spectral photo-thermal conversion system (Fe3O4/Au@SiO2) based on Fe3O4 nanospheres and SiO2-modified Au nanorods (NRs) is prepared. Owing to the strong coupling effect between Fe3O4 and different Au NRs, the wide and strong absorption band from 400 nm to 1100 nm is obtained. Under the influence of magnetic field, the temperature change of nanofluids (NFs) at different positions can be controlled. When the concentration is 0.0467 vol%, the solar energy absorption fraction reaches 96.50 %. Besides, the photothermal performance of Fe3O4/Au@SiO2 NFs at different flow rates is investigated and the results show that temperature rise decreases as increasing flow rate. Finally, a water evaporator device based Fe3O4/Au@SiO2 NFs is developed. The maximum water evaporation rate of 2.6 kg m−2 h−1 can be reached and the movement of evaporator on water can be operated using magnetic field, showing great photothermal conversion performance and recovery potential in practical applications.

NiCo@EG-based composite PCMs with boosted thermal conductivity and photothermal conversion efficiency for solar energy harvesting

The application of phase change materials (PCMs) in solar energy is hampered by challenges such as insufficient photothermal conversion efficiency, low thermal conductivity and leakage. In this study, a novel composite PCMs based on NiCo@EG were prepared to solve the problems of low thermal conductivity, high leakage rate and inefficient photothermal performance. The NiCo@EG is obtained through calcination of the product of Ni-Co-BTC in-situ on expanded graphite (EG). In the composite PCMs, the octadecanol (OD) acts as a latent heat storage unit, the EG retains its porous network structure as an encapsulating skeleton. The nickel and cobalt nanoparticles derived from Ni-Co-BTC bimetallic organic frameworks are uniformly fixed on the surface of the EG, which could not only construct multiple thermal conduction pathways, but also enhance the photon-trapping ability. Benefiting from the synergy effect of nickel, cobalt metal nanoparticles and EG, the prepared OD/NiCo@EG-550 composite PCMs display high latent heat (168.3 J/g), excellent photothermal conversion efficiency (98.71 %), and improved thermal conductivity of 12.873 W/(m·K). Furthermore, the composite PCMs demonstrate exceptional shape stability, thermal stability, and robust thermal reliability. In summary, the high-efficiency photothermal composite PCMs display significant potential in improving the utilization of solar energy.

Strong and Healable Elastomers with Photothermal-Stimulus Dynamic Nanonetworks Enabled by Subnano Ultrafine MoO3-x Nanowires.

One-dimensional nanomaterials have become one of the most available nanoreinforcing agents for developing next-generation high-performance functional self-healing composites owing to their unique structural characteristics and surface electron structure. However, nanoscale control, structural regulation, and crystal growth are still enormous challenges in the synthesis of specific one-dimensional nanomaterials. Here, oxygen-defective MoO3-x nanowires with abundant surface dynamic bonding were successfully synthesized as novel nanofillers and photothermal response agents combined with a polyurethane matrix to construct composite elastomers, thus achieving mechanically enhanced and self-healing properties. Benefiting from the surface plasmon resonance of the MoO3-x nanowires and interfacial multiple dynamic bonding interactions, the composite elastomers demonstrated strong mechanical performance (with a strength of 31.45 MPa and elongation of 1167.73%) and ultrafast photothermal toughness self-healing performance (20 s and an efficiency of 94.34%). The introduction of MoO3-x nanowires allows the construction of unique three-dimensional cross-linked nanonetworks that can move and regulate interfacial dynamic interactions under 808 nm infrared laser stimulation, resulting in controlled mechanical and healing performance. Therefore, such special elastomers with strong photothermal responses and mechanical properties are expected to be useful in next-generation biological antibacterial materials, wearable devices, and artificial muscles.

S vacancies and heterojunction modulated MoS2/C@Fe3O4 towards improved full-spectrum photo-Fenton catalysis: Enhanced interfacial charge transfer and NIR absorption

Fe3O4-based core–shell/heterojunction composites exhibit favorable photothermal catalytic performance in environmental remediation, but limited by the weak interface electron transport efficiency and poor near infrared (NIR) absorption capacity. Herein, Sv-MoS2/C@Fe3O4 core–shell composites were prepared for the first time by coating S vacancies-bearing MoS2 (Sv-MoS2) on the surface of carbon-decorated Fe3O4 microspheres (C@Fe3O4) derived from copper slag-based polymer microspheres and was used as photothermal catalyst to activate H2O2 towards chlortethromycin hydrochloride (CTC) elimination from wastewater. By virtue of the synergistic effect of the petal-like Sv-MoS2, carbon-decorated layer and multi light reflection in porous microspheres, Sv-MoS2/C@Fe3O4 exhibited excellent full spectrum absorption and carrier migration efficiency, with catalytic activity of 0.149 min−1 and H2O2 utilization rate of 93.6 %. The degradation rate is 3.9 and 3.1 times of C@Fe3O4 and MoS2/C@Fe3O4 under full light irradiation which can heat the solution from room temperature to 72.4 °C. This excellent catalytic performance is mainly originated from that the S-type heterostructure promotes the charge separation, transfer and redox ability, and enhances catalytic oxidation by regulating electron density of the interfacial carbon and reducing the energy barrier of H2O2 activation through S vacancies. Moreover, the decorated carbon layer can serve as a hot core to provide heat to Sv-MoS2 and enhance the collision chance of photogenerated carriers, thus improving the catalytic performance of Sv-MoS2/C@Fe3O4. This work provides new strategies for constructing heterojunction materials with fast electron transport efficiency and using solar energy for environmental remediation.

Optically selective catalyst design with minimized thermal emission for facilitating photothermal catalysis

Converting solar energy into fuels is pursued as an attractive route to reduce dependence on fossil fuel. In this context, photothermal catalysis is a very promising approach through converting photons into heat to drive catalytic reactions. There are mainly three key factors that govern the photothermal catalysis performance: maximized solar absorption, minimized thermal emission and excellent catalytic property of catalyst. However, the previous research has focused on improving solar absorption and catalytic performance of catalyst, largely neglected the optimization of thermal emission. Here, we demonstrate an optically selective catalyst based Ti3C2Tx Janus design, that enables minimized thermal emission, maximized solar absorption and good catalytic activity simultaneously, thereby achieving excellent photothermal catalytic performance. When applied to Sabatier reaction and reverse water-gas shift (RWGS) as demonstrations, we obtain an approximately 300% increase in catalytic yield through reducing the thermal emission of catalyst by ~70% under the same irradiation intensity. It is worth noting that the CO2 methanation yield reaches 3317.2 mmol gRu−1 h−1 at light power of 2 W cm−2, setting a performance record among catalysts without active supports. We expect that this design opens up a new pathway for the development of high-performance photothermal catalysts.

Durable microstructure-based superhydrophobic composite with photothermal performance for multifunctional application

Nowadays, multifunctional superhydrophobic coating has drawn widespread attention by virtue of its great water-repellent property, whereas the fragile mechanical and chemical durability of superhydrophobic coating greatly limits its practical application. Herein, a robust and multifunctional superhydrophobic composite coating (CFRE-SP@Fe3O4) with anti-corrosion, delay-icing and self-deicing performance is constructed via simple imprinting-demolding process on the carbon fiber reinforced epoxy resin (CFRE) surface and post-deposition modification with polydimethylsiloxane (PDMS) and epoxy resin modified Fe3O4 nanoparticles. The obtained CFRE-SP@Fe3O4 coating displays a superhydrophobic property with a WCA of 155° ± 1.2°. By virtue of the protection effect of the robust micro-grid structures for the inner superhydrophobic Fe3O4 nanoparticles (SP@Fe3O4), the CFRE-SP@Fe3O4 coating still maintains great superhydrophobicity after linear friction for 100 times. Additionally, compared with the carbon steel treated with CFRE, the impedance modulus at lowest frequency of CFRE-SP@Fe3O4 coating treated group further increase with a value of 107 Ω·cm2, confirming the excellent anti-corrosion performance. Owing to the air pocket captured by the micro-/nanostructure on the superhydrophobic surface, the icing time of the CFRE-SP@Fe3O4 surfaces extends from 60 s to 2130 s. Moreover, combined with the photothermal conversion performance of carbon fiber and Fe3O4 nanoparticles, the ice on the CFRE and CFRE-SP@Fe3O4 coatings surfaces begin to melt 137 s, displaying the excellent self-deicing performance.

Titanium dioxide/graphene oxide synergetic reinforced composite phase change materials with excellent thermal energy storage and photo-thermal performances

The development of advanced composite solid-solid phase change materials (SSPCMs) is urgent to explore for improving solar energy harvesting and storage. Herein, novel composite SSPCMs with synergetic cross-linking structure were fabricated through polymerization using GO and TiO2 constructed on the polyurethane framework skeleton. GO and TiO2 synergetic enhanced polymer framework played a role as skeletal structure to encapsulate PEG in the molecular chains, and provided as highly thermal conductive pathways for the composite SSPCMs. TiO2 nanoparticles performed as extended surface on the skeletal structure for further improvement in thermal conductivity. The composite SSPCMs exhibited a remarkably improved thermal conductivity as high as 0.7 W/(m‧K) and fast thermal response rate. The good light adsorption property of TiO2 enhanced the light absorbance efficiency of the composite SSPCMs by 94.4%. And the photo-thermal conversion efficiency of the composite SSPCMs highly reached 93.5%. Meanwhile, the composite SSPCMs exhibited excellent anti-leakage performance and shape stability under high temperature. Consequently, the as-prepared composite SSPCMs possessed a potential for applications in thermal energy storage and solar energy utilization systems.

Combined Chemo- and Photothermal Therapies of Non-Small Cell Lung Cancer Using Polydopamine/Au Hollow Nanospheres Loaded with Doxorubicin.

The chemotherapeutic agent doxorubicin (DOX) is limited by its cardiotoxicity, posing challenges in its application for non-small cell lung cancer (NSCLC). This study aims to explore the efficacy of polydopamine/Au nanoparticles loaded with DOX for chemotherapy and photothermal therapy in NSCLC to achieve enhanced efficacy and reduced toxicity. Hollow polydopamine (HPDA)/Au@DOX was synthesized via polydopamine chemical binding sacrificial template method. Morphology was characterized using transmission electron microscopy, particle size and potential were determined using dynamic light scattering, and photothermal conversion efficiency was assessed using near-infrared (NIR) thermal imaging. Drug loading rate and in vitro drug release were investigated. In vitro, anti-tumor experiments were conducted using CCK-8 assay, flow cytometry, and live/dead cell staining to evaluate the cytotoxicity of HPDA/Au@DOX on A549 cells. Uptake of HPDA/Au@DOX by A549 cells was detected using the intrinsic fluorescence of DOX. The in vivo anti-metastasis and anti-tumor effects of HPDA/Au@DOX were explored in mouse lung metastasis and subcutaneous tumor models, respectively. HPDA/Au@DOX with a particle size of (164.26±3.25) nm, a drug loading rate of 36.31%, and an encapsulation efficiency of 90.78% was successfully prepared. Under 808 nm laser irradiation, HPDA/Au@DOX accelerated DOX release and enhanced uptake by A549 cells. In vitro photothermal performance assessment showed excellent photothermal conversion capability and stability of HPDA/Au@DOX under NIR laser irradiation. Both in vitro and in vivo experiments demonstrated that the photothermal-chemotherapy combination group (HPDA/Au@DOX+NIR) exhibited stronger anti-metastatic and anti-tumor activities compared to the monotherapy group (DOX). HPDA/Au@DOX nanosystem demonstrated excellent photothermal effect, inhibiting the growth and metastasis of A549 cells. This nanosystem achieves the combined effect of chemotherapy and photothermal, making it promising for NSCLC treatment.

A morphologically transformable hypoxia-induced radical anion for tumor-specific photothermal therapy

Tumor microenvironment activatable therapeutic agents and their effective tumor accumulation are significant for selective tumor treatment. Herein, we provide an unadulterated nanomaterial combining the above advantages. We synthesize a perylene diimide (PDI) molecule substituted by glutamic acid (Glu), which can self-assemble into small spherical nanoparticles (PDI-SG) in aqueous solution. PDI-SG can not only be transformed into nanofibers at low pH conditions but also be reduced to PDI radical anion (PDI·‒), which exhibits strong near-infrared absorption and excellent photothermal performance. More importantly, PDI-SG can also be reduced to PDI·‒ in hypoxic tumors to ablate the tumors and minimize the damage to normal tissues. The morphological transformation from small nanoparticles to nanofibers makes for better tumor accumulation and retention. This work sheds light on the design of tumor microenvironment activatable therapeutics with precise structures for high-performance tumor therapy.

Evaluation of the energy flow characteristics and efficiency of photothermal functional phase change materials for efficient solar thermal harvesting

Photothermal functional phase change materials (PCMs) have attracted considerable attention due to their large energy density, which can solve the inherent imbalance defects of solar energy. However, the efficiency determination of the PCM-based photothermal utilization process (including photon absorption, photothermal conversion, thermal storage, and thermal release) is still unclear, especially with different or even contradictory quantitative indexes for the same process, resulting in inaccurate photothermal utilization performance and unfair comparison in various efforts. Herein, we clarified the photothermal utilization sub-processes of phase change composites via optical characterizations and photothermal conversion experiments and highlighted the energy dissipation mechanism of photothermal conversion process by fluorescence and femtosecond transient absorption examination. Besides, the energy flow features of these sub-processes were explored by determining the energy flow and optical/thermal losses. More importantly, we standardized the efficiency of the four sub-processes by proposing evaluation indexes and established the relationship among the four sub-processes to derive the total photothermal utilization efficiency. This work provides a paradigm for a comprehensive investigation of PCM-based photothermal utilization systems, especially establishing consistent criteria for subsequent efficiency determination, laying a solid foundation for developing and quantifying solar thermal utilization systems.

Performance investigation of solution-processed semi-transparent perovskite solar cells in building sectors

Semi-transparent perovskite solar cell (PSC) windows have received much attention from scholars due to their remarkable power generation capacity and thermal insulation performance. However, considering the complexity of their fabrication process, and the significant decrease in power generation efficiency when scaling up to large-sized solar modules. To solve the above problems, this study developed a scalable production technological process to prepare translucent PSC modules, in which large-area chalcogenide thin films were prepared by a scratch-coating method. The prepared PSC module has an average visible light transmittance of 20.1 % and shows a maximum power conversion efficiency of 3.92 %. Experimental tests were conducted to investigate its photo-thermal regulation performance concerning the existing common window. The results show that the newly developed photovoltaic window reduces the indoor air temperature by 1.4 °C while the illuminance is reduced by about 59.2 % compared to the common window. A further simulation is performed by Energyplus, with a conclusion that PSC windows can decrease glare probability by 24.7 %–45.7 %, diminish building energy usage by 26.6 %–59.6 %, and achieve up to 469.9 kWh power generation in Harbin, China. The investigation of this paper paves the technical and foundational way for the large-scale application of PSC in building sectors.