金、银纳米结构的可控合成及其光-热效应

金（Au）、银（Ag）纳米结构在近红外区中存在较强的可控表面等离子体共振吸收特性。利用近红外光的光-热效应，Au，Ag纳米结构在近红外特定波长激光的照射下，较高的光-热转换效率能达到光热治疗的要求。文中分别利用“种子”法和水热法合成了纵向表面等离子共振（Longitudinal surface plasman resonance，SPRI，）峰在650～1100nm范围可调的Au纳米棒和SPR峰在650～850nm范围的Ag纳米结构。在近红外（如808，1064nm）激光照射下，通过改变激光功率、照射时间，记录胶体溶液的温度变化，并与水在相同辐照条件下的温度变化对比。SPR。下，805nm的Au纳米棒胶体溶液在小功率（0．8w）808nm激光照射下，溶液温度可从室温升高到约57℃；在高功率激光（1064nm，8w）辐照下，Au纳米棒很快退化成颗粒，SPR。吸收峰消失。Ag纳米片和Ag纳米立方体在808nm激光（〉1w）辐照下，均具有一定的光-热效率，但效率都低于Au纳米棒胶体的光-热效率。三角形Ag纳米片在激光作用下出现截角或枝晶，而Ag纳米立方体无明显变化。

紫外写入光纤布拉格光栅的光-热效应

提出了一种测量光纤布拉格光栅的光一热效应的新方法，并利用它对一个实际的紫外写入光纤布拉格光栅的光一热效应进行了实验研究。利用980nm半导体激光器作为抽运源、两个紫外写入光纤布拉格光栅作为反射镜、一段10m长的掺铒光纤作为增益介质，构建了分布布拉格反射光纤激光器。通过合理设计，在分布布拉格反射光纤激光器工作的同时，获得了所使用的光纤布拉格光栅的反射光谱。实验结果显示，当抽运功率为100mw时，光一热效应导致所使用的紫外写入光纤布拉格光栅的反射光谱向长波长方向漂移了0．034nm。该方法可以很好地应用于光纤布拉格光栅的光热效应的测量。

A 1×4 Polymeric Digital Optical Switch Based on the Thermo-Optic Effect

We present a 1 × 4 Y-branch digital optical switch in which S-bend variable optical attenuators are integrated. The S-bend waveguides, which are always introduced to connect the switch and the standard fiber array, are made use of and designed as variable optical attenuators. A compact device with low crosstalk and larger branching-angle is obtained. The device is fabricated on the thermo-optic polymer materials,and the performance of the device is measured. With an applied driving power of less than 200mW, the device has a low crosstalk of less than - 35dB at a wavelength of 1.55 μm.

1.55μm Fabry-Perot Thermo-Optical Tunable Filter with Amorphous-Si as Cavity

A 1.55μm Fabry-Perot (F-P) thermo-optical t unable filter is fabricated.The cavity is made of amorphous silicon (a-Si) layer grown by electron-beam evaporation technique.Due to the excellent thermo-optical property of a-Si,the refractive index of the F-P cavity will be changed by heating;the transmittance resonant peak will therefore shift substantially.The measured tuning rang is 12nm, FWHM (full-width-at-half-maximum) of the transmissi on peak is 9nm,and heating efficiency is 0.1K/mW.The large FWHM is mainly due to th e non-ideal coating deposition and mirror undulation.Possible improvements to increase the efficiency of heating are suggested.

Solar-heating boosted catalytic reduction of CO_(2） under full-solar spectrum

Catalytic converting CO2 into fuels with the help of solar energy is regarded as‘dream reaction’,as both energy crisis and environmental issue can be mitigated simultaneously.However,it is still suffering from low efficiency due to narrow solar-spectrum utilization and sluggish heterogeneous reaction kinetics.In this work,we demonstrate that catalytic reduction of CO2 can be achieved over Au nanoparticles(NPs)deposited rutile under full solar-spectrum irradiation,boosted by solar-heating effect.We found that UV and visible light can initiate the reaction,and the heat from IR light and local surface-plasmon resonance relaxation of Au NPs can boost the reaction kinetically.The apparent activation energy is determined experimentally and is used to explain the superior catalytic activity of Au/rutile to rutile in a kinetic way.We also find the photo-thermal synergy in the Au/rutile system.We envision that this work may facilitate understanding the kinetics of CO2 reduction and developing feasible catalytic systems with full solar spectrum utilization for practical artificial photosynthesis.

Energy Spectrum, g Factors, Strain-Induced Level-Splittings and R-Line Thermal Shift of MgO:V^(2+)

Traditional ligand-field theory has to be improved by taking into account both pure electronic contribution and electron-phonon interaction one （including lattice-vibrational relaxation energy）. By means of improved ligand-field theory, the R line, t^322T1 and t^322T2 lines, t^22（^3T1）e^4T2, t^22（^3T1）e^4T1 and t2e^2（^4A2）4T1 bands, g factors of t^32 ^4A2 and t32E, four strain-induced level-splittings and R-line thermal shift of MgO：V^2＋ have been calculated. The results are in very good agreement with the experimental data. It is found that for MgO：V^2＋, the contributions due to electronphonon interaction （EPI） come from the first-order term; the contributions from the second-order and higher terms are insignificant. In thermal shift of R line of MgO：V^2＋, the temperature-dependent contribution due to EPI is dominant. The results obtained in this work may be used in theoretical calculations of other effects of EPI.

Photothermal self-healing polyurethane coating based on hollow nanofillers in seawater

Herein,a novel composite coating with excellent self-healing and corrosion resistance activated byphotothermal responsive hollow core-shell nanofillers was developed.A photothermal nanofiller(Co_(9)S_(8)@Bi_(2)S_(3))with ahollow core-shell structure was synthesized and then added to polyurethane(PU)to prepare PU-Co_(9)S_(8)@Bi_(2)S_(3)compositecoating.Applying 808 nm near-infrared irradiation induces a photothermal effect in Co_(9)S_(8)@Bi_(2)S_(3),which subsequentlyinitiates the reconstruction of reversible hydrogen bonds,facilitating the self-healing of coating scratches.The excellentphotothermal self-healing performance of PU-Co_(9)S_(8)@Bi_(2)S_(3)coating was demonstrated by scratch tests and moleculardynamics simulations.The electrochemical impedance spectroscopy test results showed that the PU-Co_(9)S_(8)@Bi_(2)S_(3)coating has good self-healing and anti-corrosion properties.The low-frequency impedance modulus of the coating afterthree self-healing sessions was still close to 109Ω·cm^(2)after 30 d of immersion in seawater.This study provides a newstrategy for developing multi-cycle self-healing coatings triggered by photothermal effects.

Temperature sensor based on polymer thin film optical waveguide

Based on attenuated total reflection （ATR） and thermo-optic effect, the polymeric thin film planar optical waveguide is used as the temperature sensor, and the factors influencing the sensitivity of the temperature sensor are comprehensively analyzed. Combined with theoretical analysis and experimental investigation, the sensitivity of the temperature sensor is related to the thicknesses of the upper cladding layer, the waveguide layer, the optical loss of the polymer material and the guided wave modes. The results show that the slope value about reflectivity and temperature, which stands for the sensitivity of the polymer thin film temperature sensor, is associated with the waveguide film thickness and the guided wave modes, and the slope value is the highest in the zero reflectance of a certain transverse electric （TE） mode. To improve the sensitivity of the temperature sensor, the sensor＇s working incident light exterior angle α should be chosen under a certain TE mode with the reflectivity to be zero. This temperature sensor is characterized by high sensitivity and simple structure and it is easily fabricated.

Functionalized Gold Nanorods for Tumor Imaging and Targeted Therapy

Gold nanorods,as an emerging noble metal nanomaterial with unique properties,have become the new exciting focus of theoretical and experimental studies in the past few years.The structure and function of gold nanorods,especially their biocompatibility, optical property,and photothermal effects,have been attracting more and more attention.Gold nanorods exhibit great potential in applications such as tumor molecular imaging and photothermal therapy.In this article,we review some of the main advances made over the past few years in the application of gold nanorods in surface functionalization,molecular imaging,and photothermal therapy. We also explore other prospective applications and discuss the corresponding concepts,issues,approaches,and challenges,with the aim of stimulating broader interest in gold nanorod-based nanotechnology and improving its practical application.

Synergetic photocatalytic and thermocatalytic reforming of methanol for hydrogen production based on Pt@TiO_(2) catalyst

In order to efficiently produce H_(2),conventional methanol‐water thermocatalytic(TC)reforming requires a very high temperature due to high Gibbs free energy,while the energy conversion efficiency of methanol‐water photocatalytic(PC)reforming is far from satisfaction because of the kinetic limitation.To address these issues,herein,we incorporate PC and TC processes together in a specially designed reactor and realize simultaneous photocatalytic/thermocatalytic(PC‐TC)reforming of methanol in an aqueous phase.Such a design facilitates the synergetic effect of the PC and TC process for H_(2) production due to a lower energy barrier and faster reaction kinetics.The methanol‐water reforming based on the optimized 0.05%Pt@TiO_(2) catalyst delivers an outstanding H_(2) production rate in the PC‐TC process(5.66μmol H_(2)·g^(‒1) catalyst·s^(‒1)),which is about 3 and 7 times than those of the TC process(1.89μmol H_(2)·g^(‒1) catalyst·s^(‒1))and the PC process(0.80μmol H_(2)·g^(‒1) catalyst·s^(‒1)),respectively.Isotope tracer experiments,active intermediate trapping experiments,and theoretical calculations demonstrate that the photo‐generated holes and hydroxyl radicals could enhance the methanol dehydrogenation,water molecule splitting,and water‐gas shift reaction,while high temperature accelerates reaction kinetics.The proposed PC‐TC reforming of methanol for hydrogen production can be a promising technology to solve the energy and environmental issue in the closed‐loop hydrogen economy in the near future.

Effect of Thermal Defocusing on Backward Stimulated Raman Scattering in CH4

The conversion efficiency of stimulated Raman scattering （SRS） in CH4 is studied by using a single longitudinal mode second-harmonic Nd：YAG laser （532 nm, linewidth 0.003 cm^-1, pulse-width （FWHM） 6.5 ns）. Due to the heat release from vibrationally excited particles, SRS processes often suffer from the thermal defocusing effect （TDE）. In view of 6.5 ns laser pulse width is much shorter than the vibrational relaxation time of CH4 molecules, TDE can only affect the SRS processes afterwards. In the cases of low laser repetition, TDE will be not serious, because it will be removed by the thermal diffusion in Raman medium before the next pulse arrives. At the laser repetition rate 2 Hz, CH4 pressure 1.1 MPa and pump laser energy 95 mJ, the quantum conversion efficiency of backward first-Stokes （BS1） has attained 73%. This represents the highest first-stokes conversion efficiency in CH4. Furthermore, due to the relaxation oscillation, the BS1 pulses are narrowed to about 1.2 ns. As a result, the BS1 peak power turns out to be 2.7 times that of the pump. Its beam quality is also much better and is only slightly affected by TDE. This reason is that BS1 represents a wave-front-reversed replica of the pump beam, which can compensate the thermal distortions in Raman amplify process. Under the same conditions, but pump laser repetition rate as 10 Hz, the conversion efficiency of BS1 goes down to 36% due to TDE. From this study, we expect that a well-behaved 630 nm Raman laser may be designed by using a closed CH4/He circulating-cooling system, which may have some important applications.

Practical Realization of a Hybrid Solution for Photovoltaic and Photothermal Conversion

In this paper, an idea and a realization of a hybrid Operational solar system is presented and practically verified discussed on the base of the performance and efficiency results, is confirmed. solution for photovoltaic and photothermal conversion is presented. by the series of experiments. Improvements of the construction are The synergy effect ofphotothermal and photovoltaic part cooperation

Substituent Effect on Infrared Spectra and Thermodynamic Properties of Polynitroamino Substituted Cyclopentane and Cyclohexane

Density functional theory method was employed to study the effect of the nitroamino group as a substituent in cyclopentane and cyclohexane, which usually construct polycyclic or caged nitramines. Based on the optimized molecular structures of two groups of monocyclic nitramines at the B3LYP/6-31G^＊＊ level, the infrared （IR） spectra were obtained and assigned by harmonic vibrational analysis. The calculated results agree reasonably with the available experimental data. According to the principles of statistic thermodynamics, thermodynamic properties were derived from the IR spectra, which were linearly correlated with the number of nitroamino groups as well as the temperature. The contributions of nitroamino groups to thermodynamic properties are in accord with the group additivity.

Rapid eradication of antibiotic-resistant bacteria and biofilms by MXene and near-infrared light through photothermal ablation

With the development and rising of antimicrobial resistance,rapid and effective killings of bacteria are urgently needed,especially for antibiotic-resistant bacteria and bacterial biofilms that are usually hard to be treated with conventional antibiotics.Here,a rapid and broad-spectrum antibacterial strategy is demonstrated through photothermal ablation with MXene and light.Ti3C2 MXenes,when combined with 808 nm light,show significant antibacterial effects in just 20 min.The antibacterial strategy is effective to 15 bacterial species tested,including methicillin-resistant Staphylococcus aureus(MRSA)and vancomycin-resistant Enterococci(VRE).In addition,the rapid antibacterial strategy works for MRSA biofilms,by damaging the structures as well as killing bacteria in biofilms.Furthermore,the investigation of the antibacterial mechanisms shows that Ti3C2 with light kills bacteria mainly physically through inserting/contact and photothermal effect.This work broadens the potential applications of MXene and provides a way to eradicate bacteria and biofilms physically,without the likelihood of resistance development.

High-performance salt-resistant solar interfacial evaporation by flexible robust porous carbon/pulp fiber membrane

Solar evaporation has emerged as an attractive technology to produce freshwater by utilizing renewable solar energy.However,it remains a huge challenge to develop efficient solar steam generators with good flexibility,low cost and remarkable salt resistance.Herein,we prepare flexible,robust solar membranes by filtration of porous carbon and commercial paper pulp fiber.The porous carbon with well-defined structures is prepared through controlled carbonization of biomass/waste plastics by eutectic salts.We prove the synergistic effect of porous carbon and paper pulp fiber in boosting solar evaporation performance.Firstly,the porous carbon displays a high light absorption,while the paper pulp fiber with good hydrophilicity effectively promotes the transport of water.Secondly,the combination between porous carbon and paper pulp fiber reduces the water vaporization enthalpy by 20%,which is important to significantly improve the evaporation performance.As a proof of concept,the porous carbon/paper pulp fiber membrane possesses a high evaporation rate of 1.8 kg m^(-2)h^(-1)under 1 kW m^(-2)irradiation.Thirdly,the good flexibility and mechanical property of paper pulp fiber enable the solar membrane to work well under extreme conditions(e.g.,after 20 cycles of folding/stretching/recovery).Lastly,due to the super-hydrophilicity and superwetting,the hybrid membrane exhibits the exceptional salt resistance and long-term stability in continuous seawater desalination,e.g.,for 50 h.Importantly,a large-scale solar desalination device for outdoor experiments is developed to produce freshwater.Consequently,this work provides a new insight into developing advanced flexible solar evaporators with superb performance in seawater desalination.

Two-dimensional Pd-based nanomaterials for bioapplications

Noble metal nanomaterials have been extensively explored in cancer diagnostic and therapeutic applica- tions owing to their unique physical and chemical properties, such as facile synthesis, straightforward surface functionalization, strong photothermal effect, and excellent biocompatibility. Herein, we summa- rize the recent development of two-dimensional （2D） Pd-based nanomaterials and their applications in cancer diagnosis and therapy. Different synthetic strategies for Pd nanosheets and the related nanostruc- tures, including Pd@Au, Pd@Ag nanoplates and mesocrystalline Pd nanocomlla, are first discussed. Together with their unique properties, the potential bioapplications of these 2D Pd nanomaterials are then demonstrated. With strong absorption in near-infrared （NIR） region, these nanomaterials have great potentials in cancer photothermal therapy （PTr）. They also readily act as contrast agents in photoacoustic （PA） imaging or X-ray computed tomography （CT） to achieve image-guided cancer therapy. Moreover, significant efforts have been devoted to studying the combination of PTr and other treatment modalities （e.g., chemotherapy or photodynamic therapy） based on Pd nanomaterials. The remarkable synergistic or collaborative effects to achieve better therapeutic efficacy are discussed as well. Additionally, the biosaf- ety of 2D Pd-based nanomaterials in vitro and in vivo was evaluated. Finally, challenges for the applica- tions of Pd-based nanomaterials in cancer diagnosis and therapy, and future research prospects are highlighted.

Ultrasensitive iron-based magnetic resonance contrast agent constructed with natural polyphenol tannic acid for tumor theranostics

Because of the toxicity of Gd(Ⅲ)complexes and the poor T1 magnetic resonance imaging(MRI)contrast of superparamagnetic iron oxide,the development of new stable,non-toxic,and efficient contrast agents is desirable.Herein,tannic acid(TA),a large natural polyphenol,and bovine serum albumin(BSA)were used to construct non-toxic Fe(Ⅲ)complexes with increased relaxivity based on a strategy slowing the molecular spin.Compared with the commercial T1 contrast agent Magnevist■,TA-Fe@BSA not only exhibits comparable T1 MRI contrast enhancement under 0.5,1 and 7 T magnetic fields both in vitro and in vivo,but also has better stability and biocompatibility.Moreover,TA-Fe@BSA with near-infrared(NIR)absorption demonstrates efficient tumor ablation via photothermal effects.These results demonstrate their strong potential as an alternative T1 MRI contrast agent and tumor theranostics agent in clinical settings.

All-organic composites with strong photoelectric response over a wide spectral range

2-hydroxynaphthylidene-1′-naphthylamine(HNAN) and –NO_(2) modified HNAN(HNAN-NO_(2)) Schiff base compounds were synthesized and exhibited strong visible light absorption(<650 nm). These compounds were added to poly(vinylidene fluoride-trifluoroethylene)(P(VDF-Tr FE))ferroelectric polymer, obtaining composites with high photoelectric response under visible and infrared light. It was found that the modification of HNAN by the nitro group and the poling of the composites under a high electric field can greatly enhance the photoelectric response of the composites. The composites can generate high photovoltages of 1386 and352.7 mV under irradiation with near-infrared light(915 nm)and green light(532 nm). The mechanism of the photoelectric response of the composites under green light was explored and it was found that the response originates mainly from the coupling effect of the photothermal effect of the Schiff base and the pyroelectric effect of the ferroelectric polymer. The composites, which can be utilized as photodetector materials,are promising for next-generation artificial retina applications and the sensing capability of retina can be extended in a wide wavelength range from visible to infrared light.

Solvent-and metal-directed lanthanide-organic frameworks based on pamoic acid:observation of slow magnetization relaxation,magnetocaloric effect and luminescent sensing

Two types of lanthanide coordination polymers, namely, [Ln（PA）（NO3）（DMA）3]n （Ln=Gd （1）, Dy （2）, Eu （3）, Tb （4）） （type I）, and {[Ln2（PA）3（DMF）4]＇2DMF} （Ln=Eu （5）, Tb （6）） （type II） （PA=Pamoic acid, DMA=dimethylacetamide, DMF=N,N-dimethylformamide）, have been synthesized by the reaction of Ln（NO3）a-6H20 with pamoic acid through layer diffusion method. These complexes were characterized by single crystal X-ray diffraction, infrared spectroscopy （IR）, thermogravimetric analysis （TGA）, fluorescence and magnetic measurements. Solvents and lanthanide atoms in the reaction play an important role in controlling different structures. Type I demonstrated 1-D linear chain structure connected by Ln atoms and PA ligands. Type II exhibited non-interpenetrating 3-D 6-connected 43612 nets based on binuclear [Ln2（CO2）6（DMF）4] cores. Magnetic properties of complexes 1-4 were investigated in details. Complex 1 shows significant magnetocaloric effect with -△Sm=20.37 J kg^-1 K^-1 at 3.0 K and 7 T. Complex 2 exhibits slow relaxation of the magnetization. Complexes 3-6 exhibit both ligand- and metal-centered fluorescent properties. Complex 6 demonstrates fluorescent sensing of DMF and Cu^2＋ ion.

Light-triggered plasmonic vesicles with enhanced catalytic activity of glucose oxidase for programmable photothermal/starvation therapy

Glucose oxidase(GOx)-based nanotheranostic agents hold great promise in tumor starvation and its synergistic therapy. Self-assembled plasmonic gold vesicles(GVs) with unique optical properties, large hollow cavity, and strong localized surface plasmon resonance, can be used as multi-functional nanocarriers for synergistic therapy. Herein,GOx-loaded GVs(GV-GOx) were developed for light-triggered GOx release as well as enhanced catalytic activity of GOx, achieving programmable photothermal/starvation therapy. Under near-infrared laser irradiation, the GV-GOx generated strong localized hyperthermia due to plasmon coupling effect of GVs, promoting the release of encapsulated GOx and increasing its catalytic activity, resulting in enhanced tumor starvation effect. In addition, the high photothermal effect improved the cellular uptake of GV-GOx and allowed an efficient monitoring of synergistic tumor treatment via photoacoustic/photothermal duplex imaging in vivo. Impressively, the synergistic photothermal/starvation therapy demonstrated complete tumor eradication in 4 T1 tumorbearing mice, verifying superior synergistic anti-tumor therapeutic effects than monotherapy with no apparent systemic side effects. Our work demonstrated the development of a light-triggered nanoplatform for cancer synergistic therapy.