Achieving continuous motions typically requires dynamic external stimuli for cyclic deformation,or crafted geometries with intricate modules to form a self-regulated feedback loop upon static stimulation.It is still a...Achieving continuous motions typically requires dynamic external stimuli for cyclic deformation,or crafted geometries with intricate modules to form a self-regulated feedback loop upon static stimulation.It is still a grand challenge to realize self-sustained motion in soft robots subject to unchanging environment,without complex geometry or a control module.In this work,we report soft robots based on an anisotropic cylindrical hydrogel showing self-regulated,continuous rolling motions under constant light irradiation.The robots are animated by mirror-symmetry-breaking induced by photothermal strain gradient.The self-sustained motion is attributed to the fast and reversible deformation of the gel and the autonomous refresh of the irradiated region during the rolling motion.The hydrogel robots can reach a rolling speed of 1.27 mm·s^(-1)on a horizonal surface and even climb a ramp of 18°at a speed of 0.57 mm·s^(-1)in an aqueous environment.Furthermore,the hydrogel robots can overcome an obstacle,with rolling direction controllable through irradiation angle of the light and local irradiation on selective regions.This work suggests a facile strategy to develop hydrogel robots and may provide unforeseen inspirations for the design of self-regulated soft robots by using other intelligent materials.展开更多
Light-induced electron transfer can broaden the substrate range of metalloenzyme.However,the efficiency of photo-enzyme coupling is limited by the poor combination of photosensitizer or photocatalyst with enzyme.Herei...Light-induced electron transfer can broaden the substrate range of metalloenzyme.However,the efficiency of photo-enzyme coupling is limited by the poor combination of photosensitizer or photocatalyst with enzyme.Herein,we prepared the nano-photocatalyst MIL-125-NH_(2)@Ru(bpy)by in site embedding ruthenium pyridine-diimine complex[Ru(bpy)_(3)^(2+)into metal organic frameworks MIL-125-NH_(2)and associated it with multicopper oxidase(MCO)laccase.Compared to[Ru(bpy)_(3)]^(2+),the coupling efficiency of MIL-125-NH_(2)@Ru(bpy)_(3)for enzymatic oxygen reduction increased by 35.7%.A series of characterizations confirmed that the amino group of laccase formed chemical bonds with the surface defects or hydrophobic groups of MIL-125-NH_(2)@Ru(bpy)_(3).Consequently,the tight binding accelerated the quenching process and electron transfer between laccase and the immobilized ruthenium pyridine-diimine complex.This work would open an avenue for the synthesis of MOFs photocatalyst towards photo-enzyme coupling.展开更多
With the increasing concerns to energy shortage and environmental problems in modern society,the development of cheap,clean,and sustainable energy alternatives has been attracting tremendous attention globally.Among v...With the increasing concerns to energy shortage and environmental problems in modern society,the development of cheap,clean,and sustainable energy alternatives has been attracting tremendous attention globally.Among various strategies of renewable energy exploration,solar-driven water splitting into its compositional elements H2 and O2 is an ideal approach to convert and store renewable solar energy into chemical bonds.In recent few decades,as an emerging new type of catalysts,polyoxometalates(POMs)have been widely utilized for water splitting due to their versatile synthetic methodology and highly tunable physicochemical and photochemical properties.This critical review addresses the research advances of light-driven hydrogen evolution using polyoxometalate-based catalysts,including plenary POMs,transition-metal-substituted POMs,POM@MOF composites,and POM-semiconductor hybrids,under UV,near UV and visible light irradiation.In addition,the catalytic mechanism for each reaction system has been thoroughly discussed and summarized.Finally,a comprehensive outlook of this research area is also prospected.展开更多
Light-driven synthetic micro-/nanomotors have attracted considerable attention in recent years due to their unique performances and potential applications. We herein demonstrate the dye-enhanced self-electrophoretic p...Light-driven synthetic micro-/nanomotors have attracted considerable attention in recent years due to their unique performances and potential applications. We herein demonstrate the dye-enhanced self-electrophoretic propulsion of light-driven Ti O_2–Au Janus micromotors in aqueous dye solutions. Compared to the velocities of these micromotors in pure water, 1.7, 1.5, and 1.4 times accelerated motions were observed for them in aqueous solutions of methyl blue(10-5g L^(-1)), cresol red(10^(-4)g L^(-1)),and methyl orange(10^(-4)g L^(-1)), respectively. We determined that the micromotor speed changes depending on thetype of dyes, due to variations in their photodegradation rates. In addition, following the deposition of a paramagnetic Ni layer between the Au and Ti O_2 layers, the micromotor can be precisely navigated under an external magnetic field. Such magnetic micromotors not only facilitate the recycling of micromotors, but also allow reusability in the context of dye detection and degradation.In general, such photocatalytic micro-/nanomotors provide considerable potential for the rapid detection and ‘‘on-thefly'' degradation of dye pollutants in aqueous environments.展开更多
In this paper,we report the synthesis and characterization of a wheel-shaped icosanuclear Cu-containing polyoxometalate(POM),K_(12)Li_(13)[Cu_(2)0Cl(OH)_(24)(H_(2)O)_(12)(P_(8)W_(48)O_(184))]·22H_(2)O(K_(12)Li_(1...In this paper,we report the synthesis and characterization of a wheel-shaped icosanuclear Cu-containing polyoxometalate(POM),K_(12)Li_(13)[Cu_(2)0Cl(OH)_(24)(H_(2)O)_(12)(P_(8)W_(48)O_(184))]·22H_(2)O(K_(12)Li_(13)-Cu_(2)0P_(8)W_(48)).The resulting cation-exchanged tetrabutylammonium salt of the polyoxoanion Cu_(2)0P_(8)W_(48)(TBA-Cu_(2)0P_(8)W_(48))exhibits high efficiency for visible-light-driven H_(2) production in the presence of an[Ir(ppy)2(dtbbpy)][PF_(6)]photosensitizer and a triethanolamine electron donor.Under optimal conditions,the turnover number for H_(2) production reaches~2892 after 5 h of photocatalysis and thereafter continuously increases to~13400 in a long-term 120 h reaction,representing the best performance among all reported transition-metal-substituted POM catalysts.Mechanistic studies confirm the existence of reductive and oxidative quenching processes,of which the reductive quenching pathway is dominant.Various stability tests demonstrate that the TBA-Cu_(2)0P_(8)W_(48) catalyst slowly dissociates Cu ions under turnover conditions;however,both the starting TBA-Cu_(2)0P_(8)W_(48) and its molecular decomposition products are dominant active species for efficient and long-term H_(2) production.展开更多
Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy. The materials were characterized by means of the XRD, Raman, TGA/DSC, SEM, XPS, and UV-Vis techniqu...Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy. The materials were characterized by means of the XRD, Raman, TGA/DSC, SEM, XPS, and UV-Vis techniques. The photocatalytic activities of the BiVO4 materials were evaluated for the degradation of Methyl Orange under visible-light irradiation. It is observed that pH value and surfactant exerted a great effect on the morphology and pore structure of the BiVO4 product. Spherical BiVO4 with porous structures, flower-cluster-like BiVO4, and flower-bundle-like BiVO4 were generated hydrothermally at 100°C with poly（vinyl pyrrolidone） （PVP） and urea （pH = 2） and at 160°C with NaHCO3 （pH = 7 and 8）, respectively. The PVP-derived BiVO4 showed much higher surface areas （5.0-8.4 m2/g） and narrower bandgap energies （2.45-2.49 eV）. The best photocatalytic performance of the spherical BiVO4 material with a surface area of 8.4 m2/g was associated with its higher surface area, narrower bandgap energy, higher surface oxygen vacancy density, and unique porous architecture.展开更多
Using nonequilibrium Green＇s function formalism combined first-principles density functional theory, we analyze the transport properties of a 4,4-dimethyl-6-（4-nitrophenyl）-2-phenyl-3,5-diaza-bicyclo[3.1.0]hex-2-en...Using nonequilibrium Green＇s function formalism combined first-principles density functional theory, we analyze the transport properties of a 4,4-dimethyl-6-（4-nitrophenyl）-2-phenyl-3,5-diaza-bicyclo[3.1.0]hex-2-ene molecular optical switch. The title molecule can convert between closed and open forms by visible or ultraviolet irradiation. The I-V characteristics, differential conductance, on-off ratio, electronic transmission coefficients, spatial distribution of molecular projected self-consistent Hamiltonian orbitals, HOMO-LUMO gaps, effect of electrode materials Y（111）（Y =Au, Ag and Pt） on electronic transport and different molecular geometries corresponding to the closed and open forms through the molecular device are discussed in detail. Based on the results, as soon as possible the open form translates to the closed form, and there is a switch from the ON state to the OFF state（low resistance switches to high resistance）. Theoretical results show that the donor/acceptor substituent plays an important role in the electronic transport of molecular devices. The switching performance can be improved to some extent through suitable donor and acceptor substituents.展开更多
Light carries linear momentum and can therefore exert a radiation force on the objects that it encounters. This established fact enabled optical manipulation of micro/nano-sized objects, as well as macroscopic objects...Light carries linear momentum and can therefore exert a radiation force on the objects that it encounters. This established fact enabled optical manipulation of micro/nano-sized objects, as well as macroscopic objects such as solar sails, among many other important applications. While these efforts benefit from the average value of light’s linear momentum, in this article, we propose exploiting the temporal variation of light’s linear momentum to achieve an oscillatory force of microNewton amplitude and picosecond period. We validate our proposal by analytical calculations and time domain simulations of Maxwell’s equations in the case of a high-index quarter-wave slab irradiated by a terahertz plane electromagnetic wave. In particular, we show that for plane wave terahertz light of electric field amplitude 5000 V/m and frequency 4.8 THz, an oscillatory radiation pressure of amplitude 1.8 × 10<sup>-4</sup> N/m<sup>2</sup> and 0.1 ps period can be achieved.展开更多
As blue energy,osmotic power holds tremendous potential for electricity generation via membranebased reverse electrodialysis.However,current processes suffer from low energy output mainly due to inadequate transmembra...As blue energy,osmotic power holds tremendous potential for electricity generation via membranebased reverse electrodialysis.However,current processes suffer from low energy output mainly due to inadequate transmembrane ion transport and a polarization phenomenon.Inspired by plant growth and photosynthesis,we proposed a robust heterogeneous membrane that enabled ionic-diode rectified and light-enhanced ion transport for efficient osmotic-solar energy harvesting.The membrane was rationally constructed by in-situ growth of polyaniline(PANI)onto a sulfonated matrix,creating a multiscale heterostructure that enabled the coexistence of a Janus-like architecture and semiconductor heterojunction.Benefiting from multi-asymmetries of geometry,charge,and chemistry,the membrane delivered a high unidirectional ion flow and suppressed polarization,generating an exceptional osmotic power density of up to 12.6Wm^(−2)at a 50-fold salinity gradient.Light-driven ion pumping was achieved by the synergistic photothermal and photoelectric effect of PANI heterojunction.Under light irradiation,temperature gradient and transmembrane potential were triggered simultaneously,accelerating ion movement,thereby elevating the energy conversion output.This work pioneers the development of highperformance power generators capable of harnessing energy from diverse salty sources coupled with a solar resource.展开更多
Low-temperature energy harvest,delivery,and utilization pose significant challenges for thermal management in extreme environments owing to heat loss during transport and difficulty in temperature control.Herein,we pr...Low-temperature energy harvest,delivery,and utilization pose significant challenges for thermal management in extreme environments owing to heat loss during transport and difficulty in temperature control.Herein,we propose a light-driven photo-energy delivery device with a series of photo-responsive alkoxy-grafted azobenzene-based phase-change materials(a-g-Azo PCMs).These a-g-Azo PCMs store and release crystallization and isomerization enthalpies,reaching a high energy density of 380.76 J/g even at a low temperature of-63.92℃.On this basis,we fabricate a novel three-branch light-driven microfluidic control device for distributed energy recycling that achieves light absorption,energy storage,controlled movement,and selective release cyclically over a wide range of temperatures.The a-g-Azo PCMs move remote-controllably in the microfluidic device at an average velocity of 0.11-0.53 cm/s owing to the asymmetric thermal expansion effect controlled by the temperature difference.During movement,the optically triggered heat release of a-g-Azo PCMs achieves a temperature difference of 6.6℃ even at a low temperature of-40℃.These results provide a new technology for energy harvest,delivery,and utilization in low-temperature environments via a remote manipulator.展开更多
The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Cova...The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Covalent organic frameworks(COFs)offer a promising approach for CO_(2)transformation but lack high efficiency and selectivity in the absence of metals.Here,we have incorporated a pyridine nitrogen component into the imine-COF conjugated structure(Tp Pym).This innovative system has set a record of producing a CO yield of 1565μmol g^(-1)within 6 h.The soft X-ray absorption fine structure measurement proves that Tp Pym has both better conjugation and electron cloud enrichment.The electronic structure distribution delays the charge-carrier recombination,as evidenced by femtosecond transient absorption spectroscopy.The energy band diagram and theoretical calculation show that the conduction-band potential of Tp Pym is lower and the reduction reaction of CO_(2)to CO is more likely to occur.展开更多
We report a fuel-free, near-infrared （NIR）-driven Janus microcapsule motor. The Janus microcapsule motors were fabricated by template-assisted polyelectrolyte layer-by-layer assembly, followed by spraying of a gold ...We report a fuel-free, near-infrared （NIR）-driven Janus microcapsule motor. The Janus microcapsule motors were fabricated by template-assisted polyelectrolyte layer-by-layer assembly, followed by spraying of a gold layer on one side. The NIR-powered Janus motors achieved high propulsion with a maximum speed of 42μm.s-1 in water. The propulsion mechanism of the Janus motor was attributed to the self-thermophoresis effect： The asymmetric distribution of the gold layer generated a local thermal gradient, which in turn generated thermophoretic force to propel the Janus motor. Such NIR-propelled Janus capsule motors can move efficiently in cell culture medium and have no obvious effects on the cell at the power of the NIR laser, indicating considerable promise for future biomedical applications.展开更多
We investigate the dynamic crystallization processes of colloidal photonic crystals, which are potentially invaluable for solving a number of existing and emerging technical problems in regards to controlled fabricati...We investigate the dynamic crystallization processes of colloidal photonic crystals, which are potentially invaluable for solving a number of existing and emerging technical problems in regards to controlled fabrication of crystals, such as size normalization, stability improvement, and acceleration of synthesis. In this paper, we report systematic high-resolution optical observation of the spontaneous crystallization of monodisperse polystyrene(PS) micro-spheres in aqueous solution into close-packed arrays in a static line optical tweezers. The experiments demonstrate that the crystal structure is mainly affected by the minimum potential energy of the system; however, the crystallization dynamics could be affected by various mechanical, physical, and geometric factors. The complicated dynamic transformation process from 1D crystallization to 2D crystallization and the creation and annihilation of dislocations and defects via crystal relaxation are clearly illustrated.Two major crystal growth modes, the epitaxy growth pattern and the inserted growth pattern, have been identified to play a key role in shaping the dynamics of the 1D and 2D crystallization process. These observations offer invaluable insights for in-depth research about colloidal crystal crystallization.展开更多
Algae are a large group of photo synthetic organisms responsible for approximately half of the earth’s total photosynthesis.In addition to their fundamental ecological roles as oxygen producers and as the food base f...Algae are a large group of photo synthetic organisms responsible for approximately half of the earth’s total photosynthesis.In addition to their fundamental ecological roles as oxygen producers and as the food base for almost all aquatic life,algae are also a rich source of bioactive natural products,including several clinical drugs.Cytochrome P450 enzymes(P450s) are a superfamily of biocatalysts that are extensively involved in natural product biosynthesis by mediating various types of reactions.In the post-genome era,a growing number of P450 genes have been discovered from algae,indicating their important roles in algal life-cycle.However,the functional studies of algal P450s remain limited.Benefitting from the recent technical advances in algae cultivation and genetic manipulation,the researches on P450s in algal natural product biosynthesis have been approaching to a new stage.Moreover,some photoauto trophic algae have been developed into "photo-bioreactors" for heterologous P450s to produce high-value added pharmaceuticals and chemicals in a carbon-neutral or carbon-negative manner.Here,we comprehensively review these advances of P450 studies in algae from 2000 to 2021.展开更多
Heterogeneous two-dimensional layered membranes reconstructed fromnatural or synthetic van derWaals materials enable novel ion transport mechanisms by coupling with the chemical and optoelectronic properties of the la...Heterogeneous two-dimensional layered membranes reconstructed fromnatural or synthetic van derWaals materials enable novel ion transport mechanisms by coupling with the chemical and optoelectronic properties of the layered constituents.Here,we report a light-driven and pH-dependent bidirectional ion transport phenomenon through porphyrin metal–organic framework(PMOF)and transition metal dichalcogenides-based multilayer van der Waals heterostructures with sub-nanometer ionic channels.展开更多
Remote controlled soft actuators have attracted ever-increasing interest in industrial,medical,robotics,and engineering fields.Soft actuators are charming than normal tools in executing dedicate tasks due to small vol...Remote controlled soft actuators have attracted ever-increasing interest in industrial,medical,robotics,and engineering fields.Soft actuators are charming than normal tools in executing dedicate tasks due to small volume and flexible body they have.However,it remains a challenge to design soft actuator that can adapt to multi-environments under remote stimuli with promising nano materials.Herein,we have developed a kind of near-infrared laser driven soft actuators with multi locomotive modes based on WSe2 and graphene nanosheets heterojunction.Different locomotion modes are driven by photothermal effect induced deformation to adapt to different working conditions.Moreover,the specially designed gripper driven by pulsed laser can lift a heavy load which is four times of its weight.This work broadens the choice of advanced nanomaterials for photothermal conversion of soft actuators.It is promising to realize applications including photothermal therapy and complex environment detection through the combination of the intelligent robot design and optical fiber system.展开更多
The environmental repercussions of wastewater from the dye process mean that it is very important to obtain an eco-friendly photocatalyst that would degrade wastewater.Herein,bismuth tungstate/graphene oxide(Bi_(2)WO_...The environmental repercussions of wastewater from the dye process mean that it is very important to obtain an eco-friendly photocatalyst that would degrade wastewater.Herein,bismuth tungstate/graphene oxide(Bi_(2)WO_(6)/GO)composites are fabricated through in-situ hydrothermal reaction and then the Bi_(2)WO_(6)/GO photocatalysts are deposited onto polyethylene terephthalate(PET)fabric.The obtained Bi_(2)WO_(6)/GO deposited PET fabrics are then characterized through XPS,Raman,SEM,TEM,XRD,UV-vis,BET method and photoluminescence spectroscopy(PL)to investigate their chemical and crystal structures,morphology,optical property,surface area and photochemical properties.Photocatalytic performance is studied through examining the rate of degrading rhodamine B(RhB)under visible light.Surface of PET fibers is densely covered with Bi_(2)WO_(6)/GO.Bi_(2)WO_(6)/GO deposited PET fabrics show a broad absorption band in the visible spectra.Removal rate of RhB on the Bi_(2)WO_(6)/GO deposited PET fabric is the highest with the GO content of 2 g/L(labeled as Bi_(2)WO_(6)/2 g/LGO).The result of active species experiment shows that superoxide radicals(·O_(2)^(−))plays a major role in the degradation of RhB.Moreover,Bi_(2)WO_(6)/2 g/LGO deposited PET fabric shows excellent cycle stability of photocatalytic degradation for RhB.The findings in this work can be extended to preparation other types of composite on the textile for photocatalysis,which can be applied to remove dyes in the wastewater produced by the textile or leather industry.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52325302 and 52173012)Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(No.2022SZ-FR005)。
文摘Achieving continuous motions typically requires dynamic external stimuli for cyclic deformation,or crafted geometries with intricate modules to form a self-regulated feedback loop upon static stimulation.It is still a grand challenge to realize self-sustained motion in soft robots subject to unchanging environment,without complex geometry or a control module.In this work,we report soft robots based on an anisotropic cylindrical hydrogel showing self-regulated,continuous rolling motions under constant light irradiation.The robots are animated by mirror-symmetry-breaking induced by photothermal strain gradient.The self-sustained motion is attributed to the fast and reversible deformation of the gel and the autonomous refresh of the irradiated region during the rolling motion.The hydrogel robots can reach a rolling speed of 1.27 mm·s^(-1)on a horizonal surface and even climb a ramp of 18°at a speed of 0.57 mm·s^(-1)in an aqueous environment.Furthermore,the hydrogel robots can overcome an obstacle,with rolling direction controllable through irradiation angle of the light and local irradiation on selective regions.This work suggests a facile strategy to develop hydrogel robots and may provide unforeseen inspirations for the design of self-regulated soft robots by using other intelligent materials.
基金supported by the National Natural Science Foundation of China (No.21906078)the Central Public-Interest Scientific Institution Basal Research Fund of China (No.PM-zx703–202204–104)the Gusu Innovation and Entrepreneurship Leading Talent Plan (No.ZXL2022500)。
文摘Light-induced electron transfer can broaden the substrate range of metalloenzyme.However,the efficiency of photo-enzyme coupling is limited by the poor combination of photosensitizer or photocatalyst with enzyme.Herein,we prepared the nano-photocatalyst MIL-125-NH_(2)@Ru(bpy)by in site embedding ruthenium pyridine-diimine complex[Ru(bpy)_(3)^(2+)into metal organic frameworks MIL-125-NH_(2)and associated it with multicopper oxidase(MCO)laccase.Compared to[Ru(bpy)_(3)]^(2+),the coupling efficiency of MIL-125-NH_(2)@Ru(bpy)_(3)for enzymatic oxygen reduction increased by 35.7%.A series of characterizations confirmed that the amino group of laccase formed chemical bonds with the surface defects or hydrophobic groups of MIL-125-NH_(2)@Ru(bpy)_(3).Consequently,the tight binding accelerated the quenching process and electron transfer between laccase and the immobilized ruthenium pyridine-diimine complex.This work would open an avenue for the synthesis of MOFs photocatalyst towards photo-enzyme coupling.
文摘With the increasing concerns to energy shortage and environmental problems in modern society,the development of cheap,clean,and sustainable energy alternatives has been attracting tremendous attention globally.Among various strategies of renewable energy exploration,solar-driven water splitting into its compositional elements H2 and O2 is an ideal approach to convert and store renewable solar energy into chemical bonds.In recent few decades,as an emerging new type of catalysts,polyoxometalates(POMs)have been widely utilized for water splitting due to their versatile synthetic methodology and highly tunable physicochemical and photochemical properties.This critical review addresses the research advances of light-driven hydrogen evolution using polyoxometalate-based catalysts,including plenary POMs,transition-metal-substituted POMs,POM@MOF composites,and POM-semiconductor hybrids,under UV,near UV and visible light irradiation.In addition,the catalytic mechanism for each reaction system has been thoroughly discussed and summarized.Finally,a comprehensive outlook of this research area is also prospected.
文摘Light-driven synthetic micro-/nanomotors have attracted considerable attention in recent years due to their unique performances and potential applications. We herein demonstrate the dye-enhanced self-electrophoretic propulsion of light-driven Ti O_2–Au Janus micromotors in aqueous dye solutions. Compared to the velocities of these micromotors in pure water, 1.7, 1.5, and 1.4 times accelerated motions were observed for them in aqueous solutions of methyl blue(10-5g L^(-1)), cresol red(10^(-4)g L^(-1)),and methyl orange(10^(-4)g L^(-1)), respectively. We determined that the micromotor speed changes depending on thetype of dyes, due to variations in their photodegradation rates. In addition, following the deposition of a paramagnetic Ni layer between the Au and Ti O_2 layers, the micromotor can be precisely navigated under an external magnetic field. Such magnetic micromotors not only facilitate the recycling of micromotors, but also allow reusability in the context of dye detection and degradation.In general, such photocatalytic micro-/nanomotors provide considerable potential for the rapid detection and ‘‘on-thefly'' degradation of dye pollutants in aqueous environments.
文摘In this paper,we report the synthesis and characterization of a wheel-shaped icosanuclear Cu-containing polyoxometalate(POM),K_(12)Li_(13)[Cu_(2)0Cl(OH)_(24)(H_(2)O)_(12)(P_(8)W_(48)O_(184))]·22H_(2)O(K_(12)Li_(13)-Cu_(2)0P_(8)W_(48)).The resulting cation-exchanged tetrabutylammonium salt of the polyoxoanion Cu_(2)0P_(8)W_(48)(TBA-Cu_(2)0P_(8)W_(48))exhibits high efficiency for visible-light-driven H_(2) production in the presence of an[Ir(ppy)2(dtbbpy)][PF_(6)]photosensitizer and a triethanolamine electron donor.Under optimal conditions,the turnover number for H_(2) production reaches~2892 after 5 h of photocatalysis and thereafter continuously increases to~13400 in a long-term 120 h reaction,representing the best performance among all reported transition-metal-substituted POM catalysts.Mechanistic studies confirm the existence of reductive and oxidative quenching processes,of which the reductive quenching pathway is dominant.Various stability tests demonstrate that the TBA-Cu_(2)0P_(8)W_(48) catalyst slowly dissociates Cu ions under turnover conditions;however,both the starting TBA-Cu_(2)0P_(8)W_(48) and its molecular decomposition products are dominant active species for efficient and long-term H_(2) production.
基金supported by the National Natural Science Foundation of China (No. 20973017, 21077007)the Creative Research Foundation of Beijing University of Technology (No. 00500054R4003, 005000543111501)+2 种基金the HiTech Research and Development Program (863)of China (No. 2009AA063201)the Funding Projectfor Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality (No. PHR200907105, PHR201007105,PHR201107104)the Hong Kong Baptist University (FRG2/09-10/023)
文摘Monoclinic BiVO4 with multiple morphologies and/or porous structures were fabricated using the hydrothermal strategy. The materials were characterized by means of the XRD, Raman, TGA/DSC, SEM, XPS, and UV-Vis techniques. The photocatalytic activities of the BiVO4 materials were evaluated for the degradation of Methyl Orange under visible-light irradiation. It is observed that pH value and surfactant exerted a great effect on the morphology and pore structure of the BiVO4 product. Spherical BiVO4 with porous structures, flower-cluster-like BiVO4, and flower-bundle-like BiVO4 were generated hydrothermally at 100°C with poly（vinyl pyrrolidone） （PVP） and urea （pH = 2） and at 160°C with NaHCO3 （pH = 7 and 8）, respectively. The PVP-derived BiVO4 showed much higher surface areas （5.0-8.4 m2/g） and narrower bandgap energies （2.45-2.49 eV）. The best photocatalytic performance of the spherical BiVO4 material with a surface area of 8.4 m2/g was associated with its higher surface area, narrower bandgap energy, higher surface oxygen vacancy density, and unique porous architecture.
基金Supported by the Damghan University,the Ferdowsi University of Mashhad and the Islamic Azad University of Shahrood
文摘Using nonequilibrium Green＇s function formalism combined first-principles density functional theory, we analyze the transport properties of a 4,4-dimethyl-6-（4-nitrophenyl）-2-phenyl-3,5-diaza-bicyclo[3.1.0]hex-2-ene molecular optical switch. The title molecule can convert between closed and open forms by visible or ultraviolet irradiation. The I-V characteristics, differential conductance, on-off ratio, electronic transmission coefficients, spatial distribution of molecular projected self-consistent Hamiltonian orbitals, HOMO-LUMO gaps, effect of electrode materials Y（111）（Y =Au, Ag and Pt） on electronic transport and different molecular geometries corresponding to the closed and open forms through the molecular device are discussed in detail. Based on the results, as soon as possible the open form translates to the closed form, and there is a switch from the ON state to the OFF state（low resistance switches to high resistance）. Theoretical results show that the donor/acceptor substituent plays an important role in the electronic transport of molecular devices. The switching performance can be improved to some extent through suitable donor and acceptor substituents.
文摘Light carries linear momentum and can therefore exert a radiation force on the objects that it encounters. This established fact enabled optical manipulation of micro/nano-sized objects, as well as macroscopic objects such as solar sails, among many other important applications. While these efforts benefit from the average value of light’s linear momentum, in this article, we propose exploiting the temporal variation of light’s linear momentum to achieve an oscillatory force of microNewton amplitude and picosecond period. We validate our proposal by analytical calculations and time domain simulations of Maxwell’s equations in the case of a high-index quarter-wave slab irradiated by a terahertz plane electromagnetic wave. In particular, we show that for plane wave terahertz light of electric field amplitude 5000 V/m and frequency 4.8 THz, an oscillatory radiation pressure of amplitude 1.8 × 10<sup>-4</sup> N/m<sup>2</sup> and 0.1 ps period can be achieved.
基金support of the National Natural Science Foundation of China(NSFCgrant no.21991123).
文摘As blue energy,osmotic power holds tremendous potential for electricity generation via membranebased reverse electrodialysis.However,current processes suffer from low energy output mainly due to inadequate transmembrane ion transport and a polarization phenomenon.Inspired by plant growth and photosynthesis,we proposed a robust heterogeneous membrane that enabled ionic-diode rectified and light-enhanced ion transport for efficient osmotic-solar energy harvesting.The membrane was rationally constructed by in-situ growth of polyaniline(PANI)onto a sulfonated matrix,creating a multiscale heterostructure that enabled the coexistence of a Janus-like architecture and semiconductor heterojunction.Benefiting from multi-asymmetries of geometry,charge,and chemistry,the membrane delivered a high unidirectional ion flow and suppressed polarization,generating an exceptional osmotic power density of up to 12.6Wm^(−2)at a 50-fold salinity gradient.Light-driven ion pumping was achieved by the synergistic photothermal and photoelectric effect of PANI heterojunction.Under light irradiation,temperature gradient and transmembrane potential were triggered simultaneously,accelerating ion movement,thereby elevating the energy conversion output.This work pioneers the development of highperformance power generators capable of harnessing energy from diverse salty sources coupled with a solar resource.
基金Science Foundation for Distinguished Young Scholars in Tianjin,Grant/Award Number:19JCJQJC61700National Natural Science Foundation of China,Grant/Award Numbers:52327802,52173078,51973152+1 种基金National Key R&D Program of China,Grant/Award Number:2022YFB3805702State Key Program of National Natural Science Foundation of China,Grant/Award Number:52130303。
文摘Low-temperature energy harvest,delivery,and utilization pose significant challenges for thermal management in extreme environments owing to heat loss during transport and difficulty in temperature control.Herein,we propose a light-driven photo-energy delivery device with a series of photo-responsive alkoxy-grafted azobenzene-based phase-change materials(a-g-Azo PCMs).These a-g-Azo PCMs store and release crystallization and isomerization enthalpies,reaching a high energy density of 380.76 J/g even at a low temperature of-63.92℃.On this basis,we fabricate a novel three-branch light-driven microfluidic control device for distributed energy recycling that achieves light absorption,energy storage,controlled movement,and selective release cyclically over a wide range of temperatures.The a-g-Azo PCMs move remote-controllably in the microfluidic device at an average velocity of 0.11-0.53 cm/s owing to the asymmetric thermal expansion effect controlled by the temperature difference.During movement,the optically triggered heat release of a-g-Azo PCMs achieves a temperature difference of 6.6℃ even at a low temperature of-40℃.These results provide a new technology for energy harvest,delivery,and utilization in low-temperature environments via a remote manipulator.
基金supported by the National Natural Science Foundation of China(Nos.22375031,22202037,22472023)the Fundamental Research Funds for the Central Universities(Nos.2412023YQ001,2412023QD019,2412024QD014)+1 种基金supported by grants from the seventh batch of Jilin Province Youth Science and Technology Talent Lifting Project(No.QT202305)Science and Technology Development Plan Project of Jilin Province,China(No.20240101192JC)。
文摘The light-driven CO_(2)reduction reaction(CO_(2)RR)to CO is a very effective way to address global warming.To avoid competition with water photolysis,metal-free gas-solid CO_(2)RR catalysts should be investigated.Covalent organic frameworks(COFs)offer a promising approach for CO_(2)transformation but lack high efficiency and selectivity in the absence of metals.Here,we have incorporated a pyridine nitrogen component into the imine-COF conjugated structure(Tp Pym).This innovative system has set a record of producing a CO yield of 1565μmol g^(-1)within 6 h.The soft X-ray absorption fine structure measurement proves that Tp Pym has both better conjugation and electron cloud enrichment.The electronic structure distribution delays the charge-carrier recombination,as evidenced by femtosecond transient absorption spectroscopy.The energy band diagram and theoretical calculation show that the conduction-band potential of Tp Pym is lower and the reduction reaction of CO_(2)to CO is more likely to occur.
基金This work was financially supported by the National Natural Science Foundation of China （No. 21573053）. The project was supported by State Key Laboratory of Advanced Technology for Materials Synthesis and Processing （Wuhan University of Technology）.
文摘We report a fuel-free, near-infrared （NIR）-driven Janus microcapsule motor. The Janus microcapsule motors were fabricated by template-assisted polyelectrolyte layer-by-layer assembly, followed by spraying of a gold layer on one side. The NIR-powered Janus motors achieved high propulsion with a maximum speed of 42μm.s-1 in water. The propulsion mechanism of the Janus motor was attributed to the self-thermophoresis effect： The asymmetric distribution of the gold layer generated a local thermal gradient, which in turn generated thermophoretic force to propel the Janus motor. Such NIR-propelled Janus capsule motors can move efficiently in cell culture medium and have no obvious effects on the cell at the power of the NIR laser, indicating considerable promise for future biomedical applications.
基金National 973 Program of China(2013CB632704)National Natural Science Foundation of China(NSFC)(11434017)
文摘We investigate the dynamic crystallization processes of colloidal photonic crystals, which are potentially invaluable for solving a number of existing and emerging technical problems in regards to controlled fabrication of crystals, such as size normalization, stability improvement, and acceleration of synthesis. In this paper, we report systematic high-resolution optical observation of the spontaneous crystallization of monodisperse polystyrene(PS) micro-spheres in aqueous solution into close-packed arrays in a static line optical tweezers. The experiments demonstrate that the crystal structure is mainly affected by the minimum potential energy of the system; however, the crystallization dynamics could be affected by various mechanical, physical, and geometric factors. The complicated dynamic transformation process from 1D crystallization to 2D crystallization and the creation and annihilation of dislocations and defects via crystal relaxation are clearly illustrated.Two major crystal growth modes, the epitaxy growth pattern and the inserted growth pattern, have been identified to play a key role in shaping the dynamics of the 1D and 2D crystallization process. These observations offer invaluable insights for in-depth research about colloidal crystal crystallization.
基金supported by the National Key Research and Development Program of China(2020YFA0907900)the National Natural Science Foundation of China(32000039,32025001,31972815 and 42176124)+2 种基金the Natural Science Foundation of Shandong Province(ZR2019ZD20,ZR2019ZD17 and ZR2020ZD23)the Fundamental Research Funds of Shandong University(2019GN031)the Scientific Research Fund of Binzhou Medical University(BY2021KYQD25)。
文摘Algae are a large group of photo synthetic organisms responsible for approximately half of the earth’s total photosynthesis.In addition to their fundamental ecological roles as oxygen producers and as the food base for almost all aquatic life,algae are also a rich source of bioactive natural products,including several clinical drugs.Cytochrome P450 enzymes(P450s) are a superfamily of biocatalysts that are extensively involved in natural product biosynthesis by mediating various types of reactions.In the post-genome era,a growing number of P450 genes have been discovered from algae,indicating their important roles in algal life-cycle.However,the functional studies of algal P450s remain limited.Benefitting from the recent technical advances in algae cultivation and genetic manipulation,the researches on P450s in algal natural product biosynthesis have been approaching to a new stage.Moreover,some photoauto trophic algae have been developed into "photo-bioreactors" for heterologous P450s to produce high-value added pharmaceuticals and chemicals in a carbon-neutral or carbon-negative manner.Here,we comprehensively review these advances of P450 studies in algae from 2000 to 2021.
基金supported by the National Natural Science Foundation of China(no.21975268).W.G.received a distinguished fellowship from the Youth Innovation Promotion Association of CAS.Prof.Feng Bai at Henan University is acknowledged for beneficial discussion.Profs.Gang Xu and Guan-e Wang at Fujian Institute of Research on the Structure of Matter,CAS are also acknowledged for their help with the GIXRD tests.
文摘Heterogeneous two-dimensional layered membranes reconstructed fromnatural or synthetic van derWaals materials enable novel ion transport mechanisms by coupling with the chemical and optoelectronic properties of the layered constituents.Here,we report a light-driven and pH-dependent bidirectional ion transport phenomenon through porphyrin metal–organic framework(PMOF)and transition metal dichalcogenides-based multilayer van der Waals heterostructures with sub-nanometer ionic channels.
基金This work was financed by the National Natural Science Foundation of China(No.62175225)Zhejiang Provincial Natural Science Foundation of China(No.LZ21E020004)Fundamental Research Funds for the Provincial Universities of Zhejiang,Young Top Talent Plan of Zhejiang(No.ZJWR0308004).
文摘Remote controlled soft actuators have attracted ever-increasing interest in industrial,medical,robotics,and engineering fields.Soft actuators are charming than normal tools in executing dedicate tasks due to small volume and flexible body they have.However,it remains a challenge to design soft actuator that can adapt to multi-environments under remote stimuli with promising nano materials.Herein,we have developed a kind of near-infrared laser driven soft actuators with multi locomotive modes based on WSe2 and graphene nanosheets heterojunction.Different locomotion modes are driven by photothermal effect induced deformation to adapt to different working conditions.Moreover,the specially designed gripper driven by pulsed laser can lift a heavy load which is four times of its weight.This work broadens the choice of advanced nanomaterials for photothermal conversion of soft actuators.It is promising to realize applications including photothermal therapy and complex environment detection through the combination of the intelligent robot design and optical fiber system.
基金Joint Fund of the National Natural Science Foundation of China(No.U1833118)Sichuan Science and Technology Program(2019YFG0244).
文摘The environmental repercussions of wastewater from the dye process mean that it is very important to obtain an eco-friendly photocatalyst that would degrade wastewater.Herein,bismuth tungstate/graphene oxide(Bi_(2)WO_(6)/GO)composites are fabricated through in-situ hydrothermal reaction and then the Bi_(2)WO_(6)/GO photocatalysts are deposited onto polyethylene terephthalate(PET)fabric.The obtained Bi_(2)WO_(6)/GO deposited PET fabrics are then characterized through XPS,Raman,SEM,TEM,XRD,UV-vis,BET method and photoluminescence spectroscopy(PL)to investigate their chemical and crystal structures,morphology,optical property,surface area and photochemical properties.Photocatalytic performance is studied through examining the rate of degrading rhodamine B(RhB)under visible light.Surface of PET fibers is densely covered with Bi_(2)WO_(6)/GO.Bi_(2)WO_(6)/GO deposited PET fabrics show a broad absorption band in the visible spectra.Removal rate of RhB on the Bi_(2)WO_(6)/GO deposited PET fabric is the highest with the GO content of 2 g/L(labeled as Bi_(2)WO_(6)/2 g/LGO).The result of active species experiment shows that superoxide radicals(·O_(2)^(−))plays a major role in the degradation of RhB.Moreover,Bi_(2)WO_(6)/2 g/LGO deposited PET fabric shows excellent cycle stability of photocatalytic degradation for RhB.The findings in this work can be extended to preparation other types of composite on the textile for photocatalysis,which can be applied to remove dyes in the wastewater produced by the textile or leather industry.
