查看更多>>摘要：In photocatalysis,both the photogenerated charge separation and transport and the induced light utili-zation greatly influence performance.In this work,highly ordered CdS@ZnO core-shell inverse opal(CdS@ZnO-cslO)nanocomposites have been suc-cessfully designed as a model to couple the hetero-junction system with the slow photon effect for photocatalytic H2 production.Theoretical calcula-tions and experimentation provide direct evidence for the slow photon effect in the CdS@ZnO-cslO nanocomposites.The type Ⅱ heterojunction is re-sponsible for promoting the migration and separa-tion of photogenerated charges,and the slow photon effect is in charge of enhancing light har-vesting in the CdS@ZnO-cslO nanocomposites.This synergy of two functions gives rise to a significantly enhanced photocatalytic H2 production rate under simulated solar light for the CdS@ZnO-cslO nano-composites.The highest H2 production rate reaches 48.7 mmol g-1 h-1 under simulated solar light with the benchmark performance for all reported CdS@ZnO composites.Our work provides proof-of-principle that coupling the heterojunction system with the slow photon effect can greatly enhance the photo-catalytic activity of composite photocatalysts.
查看更多>>摘要：Organic reactions in water have attracted great atten-tion due to their advantages such as unique reaction performance and environmental friendliness.Organic reactions as well as polymerizations in aqueous media have been extensively investigated,and so far,there has been a massive amount of reporting about polymerizations in water.However,reports about click polymerization in water have been rare.Herein,click polymerization of activated alkyne and aromatic amine in aqueous media is developed.The"on water"effect facilitates polymerization in aqueous media bet-ter than in organic solvents,and its mechanism is deciphered through experimental data and theoretical calculations.Water participates in the reaction and reduces the energy barrier to some extent.Besides,polymerization makes it possible for aromatic amine with low reactivity to be linked.By using this strategy,polymers with high molecular weights can be obtained in high yields(up to 95.4％).They show good thermal stability and high refractivity.They can be photode-graded.The polymers with tetraphenylethylene moie-ties show aggregation-induced emission and can be used as materials for generating photopatterns and visualizing agents for specific staining of lysosome in living cells.
查看更多>>摘要：The use of transition-metal phosphides(TMPs)as catalytic materials to accelerate kinetics of lithium polysulfide(LiPS)conversion has unique advan-tages.Nevertheless,simple and low-cost prepara-tion strategies are still required for the synthesis of novel TMPs with satisfactory performance.Impor-tantly,the in-depth understanding of the effect of intrinsic interaction between catalytic materials and LiPSs on the promoted kinetics remains limited.Herein,a novel structure of tungsten phosphide(WP)nanocrystals decorated on N,P codoped car-bon sheets(WP/NPC)with uniform dispersion is designed by a structure-oriented strategy to pro-mote LiPS redox kinetics.The electrochemical kinet-ics measurements coupled with density functional theory computations and in situ/ex situ character-izations demonstrate that the strong interaction through W-S bonding and the favorable interfacial charge state of WP-LiPSs promote the nucleation and dissociation of Li2S.Benefiting from this supe-riority,the WP/NPG-based lithium-sulfur batteries indicate significantly improved electrochemical performance with good cycling life and excellent rate capability.This work provides a methodology for the design of TMP-involved electrode materials and a fundamental understanding of the intrinsic mechanism of catalysis.
查看更多>>摘要：Spin crossover(SCO)is commonly accompanied by a synchronous phase transition.A few phase transition-coupled SCO compounds have been reported,yet the synergy between SCO and phase transition on differ-ent time scales has not been explored.Herein,we report an[Fe(H-5-CI-thsa-Et)(5-CI-thsa-Et)]·H2O(1·H2O;H2-5-CI-thsa-Et=5-chloro-salicylaldehyde ethylthiosemicarbazone)Fe(Ⅲ)complex that displays a two-dimensional supramolecular structure and SCO behavior above room temperature.Its dehydrated form 1 exhibits a two-step spin transition with a plateau in the temperature-dependent magnetization(M-T)curve at room temperature and a 51 K thermal hyster-esis loop(Tc↑↓=299/248 K)at a rate of 5 K/min.The improved SCO performance in 1 could be attributed to the stronger intralayer but weaker interlayer interac-tions,which is supported by single-crystal structural analysis and density functional theory calculations.Remarkably,complex 1 displays an unusual scan rate-dependent SCO behavior at rates of 0.5-30 K/min,in which M-Tcurve plateaus appear at lower scan rates(＜10 K/min)but vanish at faster scan rates(≥10 K/min).Scan rate-dependent differential scan-ning calorimetry,powder X-ray diffractometry,time-dependent magnetic moment decays,and infrared spectroscopy consistently reveal that the slow struc-tural relaxation is coupled with a slow crystallographic phase transition,which is the mechanism for the un-usual scan rate-dependent SCO.
查看更多>>摘要：Organic heterostructures with precisely defined com-positions,architectures,and interfaces are consid-ered promising building blocks for integrated optoelectronic devices.However,it remains a great challenge to rationally design and synthesize a het-erostructure with tunable performance for promising applications such as optoelectronic devices.Herein,we report a universal strategy for the synthesis of organic lateral heterostructures(OLHs)with tunable function and optical properties.We fabricated cocrystals based on the tunable intermolecular dis-tance(dπ-π from 3.33 to 3.48 Å)of Benzo[ghi]perylene(BGP)-based driven by arene-perfluoroarene interac-tion or charge transfer interaction;these different components were selectively constructed into organ-ic solid solution microwires or OLHs.Importantly,the solid solution microwires obtained could be epitaxi-ally grown on the BGP-tetrabromophthalicanhydride trunk microwire to construct a series of OLHs micro-wires,which led to the successful demonstration of both photonic signal conversion and optical logic gate in all-color wavelength.This work gives a new insight into the fine synthesis of heterostructures with tunable structures/performances,providing predict-able synthetic pathways to multifunctional organic heterostructures for the future realization of integrat-ed optoelectronics.
查看更多>>摘要：While supramolecular hydrogels have received grow-ing interest due to their unique dynamic features,their relatively weak mechanical properties have largely limited their biomedical applications.In this study,we propose and demonstrate a strategy to reinforce the mechanical properties of supramolecu-lar hydrogel by introducing polymeric multiple-unit linker(PMUL),which incorporates multiple supramo-lecular units into a polymeric backbone to crosslink supramolecular hydrogel.We demonstrated that PMUL can effectively improve the kinetic stability of supramolecular crosslinkers through multiple-unit in-teraction in a DNA supramolecular hydrogel model system,thus leading to higher mechanical strength.Meanwhile,the dynamic features of the supramolec-ular hydrogels have been well preserved,including shear-thinning,self-healing properties,and revers-ible thermal responsiveness.This strategy offers a simple but effective way for mechanical reinforce-ment of supramolecular hydrogels to construct nov-el biomaterials.
查看更多>>摘要：Porous organic polymers(POPs)containing catalyti-cally active sites are of paramount importance for heterogeneous catalysis.However,the catalytically active sites of reported POPs are mostly limited to mononuclear metal species.Herein,we report the reaction between catechol-containing POPs(Cat-POPs)and[CuⅠMes]n to afford the corresponding CuⅠ2-CatPOPs with a putative vicinal binuclear(cate-cholate)CuⅠ2 moiety.The resulting CuⅠ2-CatPOPs ex-hibit high Brunauer-Emmett-Teller surface areas,good stability,and excellent catalytic activity toward the aerobic oxidation of a broad range of primary and secondary alcohols under mild conditions,with either 2,2,6,6-tetramethylpiperidinyl-N-oxyl or 9-azabicyclo[3.3.0]nonane-N-oxyl as the cocatalyst.As green aer-obic oxidation catalysts,the CuⅠ2-CatPOPs are much more active than the corresponding mononuclear CuⅡ-CatPOPs,where each catecholate moiety only sup-ports one CuⅡ center;CuⅠ-ConPOPs,where the binding sites for CuⅠ is a nonvicinal 1,4-dihydroxybenzene moi-ety;and the homogeneous analogue(3,6-di-tert-butyl catecholate)CuⅠ2.These results are consistent with a proposed vicinal binuclear CuⅠ2 structure that can efficiently activate molecular oxygen for the aerobic oxidation of alcohols,mechanistically similar to that observed in dicopper-containing oxygenases.Our results demonstrate the facile preparation of POPs with binuclear catalytically active sites that function as green heterogeneous catalysts for efficient oxida-tion of alcohols.
查看更多>>摘要：Asymmetric nonfullerene acceptors(NFAs)possess larg-er dipole moments and stronger intermolecular bonding energy than their symmetric counterparts thereby mak-ing them promising candidates for high-performance polymer solar cells(PSCs).Herein,we report two efficient acceptor-donor-acceptor(A-D-A)type NFAs(M14 and M18)with asymmetric side chains that show enhanced intermolecular interactions compared with their corre-sponding counterparts(M17 and M19)based on symmet-ric side chains.Furthermore,M14 and M18 exhibit elevated lowest unoccupied molecular orbitals and smal-ler π-π stacking distances in comparison with M17 and M19,respectively.In combination with the benchmark polymer donor of PM6,the PM6:M14 blend affords super-ior charge transport properties,and more importantly,an increased power conversion efficiency(PCE)of 15.49％in comparison with the M17-based counterpart(13.01％PCE).Similarly,the asymmetric M18-based blend also shows a higher PCE of 13.00％than the M19-based blend(11.55％).Through further interface engineering,the best-performing M14-based device delivers an enhanced PCE of 16.46％,which represents a record value among all asymmetric A-D-A type NFAs.Our results provide new insights into the design of asymmetric NFAs with enhanced intermolecular interactions for high-performance PSCs.
查看更多>>摘要：The development of smart drug delivery systems(SDDSs)based on engineered nanomaterials is im-portant for clinical applications.Nevertheless,con-trollable administration of chemotherapeutic drugs for deep tumors and the avoidance of side effects caused by off-targeting during delivery remain a great challenge.Herein,a stimulus-responsive sys-tem of mesoporous nanospheres(composed of Cu@Fe2C@mSiO2)with good magnetothermal ef-fect is introduced into the tumor microenvironment.This system plays an important role in image-guided controllable targeted drug delivery that is indepen-dent of tumor depth.Aggregation-induced emission luminogen-based fluorescence imaging and magnet-ic resonance imaging were utilized since these tech-niques visualize the delivery process in real time.In addition,the degraded nanocarriers showed high catalytic activity for Fenton and Fenton-like reac-tions,upregulating the level of hydroxyl radicals(·OH)in cancer cells to realize chemodynamic ther-apy.The induced·OH led to the overexpression of pho-STAT3,activating the STAT3 signaling pathway,eventually inducing cancer cell apoptosis.Through metabolic monitoring,this SDDS is removed from the body after its degradation in vivo.The synergistically enhanced therapeutic effect was obtained in the chemo-chemodynamic therapy of 4T1 tumor-bearing mice,offering a platform for efficient cancer therapy with a personalized theranostic strategy.
查看更多>>摘要：All-fused-ring π-conjugated molecules have received considerable attention because of their unique elec-tronic structures,low conformation disorder,and ex-cellent optoelectronic properties.Most all-fused-ring molecules are p-type organic semiconductors and possess medium bandgaps.In this work,we design and synthesize an all-fused-ring molecule(FM1)with an n-type property and narrow bandgap,which is a 10-fused-ring system composed of one electron-deficient benzotriazole core,two electron-rich thie-nopyrrole bridging units,and two electron-deficient malononitrile-functionalized end-cappers.FM1 exhi-bits low-lying highest occupied molecular orbit/lowest unoccupied molecular orbit energy levels of-5.77 eV/-3.89 eV,high electron mobility of 6.0 x 10-4 cm2 V-1 s-1,an optical bandgap of 1.50 eV,and a maximum absorption wavelength of 769 nm.Because of the all-fused-ring skeleton,FM1 shows superior photostability and chemical stability.We use FM1 as an electron acceptor and successfully construct or-ganic solar cell(OSC)devices with a decent power conversion efficiency(PCE)of 10.8％.Most important-ly,the intrinsic stability of FM1 leads to its excellent OSC device stability.After irradiation with simulated solar light for 16 h,while control of the OSC device of the state-of-the-art small molecule electron acceptor shows a 46％decrease of PCE,the FM1's unen-capsulated OSC device exhibits only a 9％decrease of PCE.
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