Robust photo-assisted removal of NO at room temperature:Experimental and density functional theory calculation with optical carrier

Photo-assisted SCR(PSCR) offers a potential solution for removal of NO at room temperature. MnTiO_(x)as PSCR catalyst exhibits superior performance with NO removal of 100% at the room temperature. Electron paramagnetic resonance(EPR) analysis revealed the presence of numerous oxygen vacancies on MnTiO_(x). Optical carrier density functional theory(DFT) calculations showed that the threedimensional orbital hybridization of Mn and Ti is significantly enhanced under light irradiation. The MnTiO_(x)catalyst exhibited excellent electron–hole separation ability, which can adsorbe NH_(3)and dissociate to form NH_(2)fragments and H atoms. In-situ diffuse reflectance infrared fourier-transform spectroscopy(DRIFTS) indicated that the optical carrier enhanced NH_(3)adsorption on MnTiO_(x), which makes it possess excellent PSCR activity. This work provided an additional strategy to NO removal with PSCR catalysts and showed potential for use in photocatalysis.

Battery Separators Functionalized with Edge-Rich MoS2/C Hollow Microspheres for the Uniform Deposition of Li2S in High-Performance Lithium-Sulfur Batteries

As promising energy storage systems,lithium-sulfur(Li-S)batteries have attracted significant attention because of their ultra-high energy densities.However,Li-S battery suffers problems related to the complex phase conversion that occurs during the charge-discharge process,particularly the deposition of solid Li2S from the liquid-phase polysulfides,which greatly limits its practical application.In this paper,edge-rich MoS2/C hollow microspheres(Edg-MoS2/C HMs)were designed and used to functionalize separator for Li-S battery,resulting in the uniform deposition of Li2S.The microspheres were fabricated through the facile hydrothermal treatment of MoO3-aniline nanowires and a subsequent carbonization process.The obtained Edg-MoS2/C HMs have a strong chemical absorption capability and high density of Li2S binding sites,and exhibit excellent electrocatalytic performance and can effectively hinder the polysulfide shuttle effect and guide the uniform nucleation and growth of Li2S.Furthermore,we demonstrate that the Edg-MoS2/C HMs can effectively regulate the deposition of Li2S and significantly improve the reversibility of the phase conversion of the active sulfur species,especially at high sulfur loadings and high C-rates.As a result,a cell containing a separator functionalized with Edg-MoS2/C HMs exhibited an initial discharge capacity of 935 mAh g-1 at 1.0 C and maintained a capacity of 494 mAh g-1 after 1000 cycles with a sulfur loading of 1.7 mg cm-2.Impressively,at a high sulfur loading of 6.1 mg cm-2 and high rate of 0.5 C,the cell still delivered a high reversible discharge capacity of 478 mAh g-1 after 300 cycles.This work provides fresh insights into energy storage systems related to complex phase conversions.

Decorating ketjen black with ultra-small Mo_(2)C nanoparticles to enhance polysulfides chemisorption and redox kinetics for lithium-sulfur batteries

The low sulfur utilization and fast capacity fading resulting from the sluggish redox reaction and abominable polysulfides shuttle greatly hinder the practical applications of lithium-sulfur(Li-S) batteries.Herein, we develop a facile "in-situ growth" method to decorate ultra-small Mo2 C nanoparticles(USMo2 C) on the surface of Ketjen Black(KB) to functionalize the commercial polypropylene(PP) separators,which can accelerate the redox kinetics of lithium polysulfides conversion and effectively increase the utilization of sulfur for Li-S batteries. Importantly, the US-Mo2 C nanoparticles have abundant sites for chemical adsorption towards polysulfides and the conductive carbon networks of KB have cross-linked pore channels, which can promote electron transport and provide physical barrier and volume expansion space for polysulfides. Due to the combined effects of the US-Mo2 C and KB, Li-S cells employing the multifunctional PP separators modified with KB/US-Mo2 C composite(KB/US-Mo2 C@PP) exhibit a high specific capacity(1212.8 mAh g^(-1) at 0.2 C), and maintain a reversible capacity of 1053.3 m Ah g^(-1) after 100 cycles.More importantly, the KB/US-Mo2 C@PP cells with higher sulfur mass loading of 4.9 mg cm^(-2) have superb areal capacity of 2.3 mAh cm^(-2). This work offers a novel and promising perspective for high-performance Li-S batteries from both the shuttle effect and the complex polysulfides conversion.

Engineering of a NIR-activable hydrogel-coated mesoporous bioactive glass scaffold with dual-mode parathyroid hormone derivative release property for angiogenesis and bone regeneration

Osteogenesis,osteoclastogenesis,and angiogenesis play crucial roles in bone regeneration.Parathyroid hormone(PTH),an FDA-approved drug with pro-osteogenic,pro-osteoclastogenic and proangiogenic capabilities,has been employed for clinical osteoporosis treatment through systemic intermittent administration.However,the successful application of PTH for local bone defect repair generally requires the incorporation and delivery by appropriate carriers.Though several scaffolds have been developed to deliver PTH,they suffer from the weaknesses such as uncontrollable PTH release,insufficient porous structure and low mechanical strength.Herein,a novel kind of NIR-activable scaffold(CBP/MBGS/PTHrP-2)with dual-mode PTHrP-2(a PTH derivative)release capability is developed to synergistically promote osteogenesis and angiogenesis for high-efficacy bone regeneration,which is fabricated by integrating the PTHrP-2-loaded hierarchically mesoporous bioactive glass(MBG)into the N-hydroxymethylacrylamide-modified,photothermal agent-doped,poly(N-isopropylacrylamide)-based thermosensitive hydrogels through assembly process.Upon on/off NIR irradiation,the thermoresponsive hydrogel gating undergoes a reversible phase transition to allow the precise control of on-demand pulsatile and long-term slow release of PTHrP-2 from MBG mesopores.Such NIR-activated dual-mode delivery of PTHrP-2 by this scaffold enables a well-maintained PTHrP-2 concentration at the bone defect sites to continually stimulate vascularization and promote osteoblasts to facilitate and accelerate bone remodeling.In vivo experiments confirm the significant improvement of bone reparative effect on critical-size femoral defects of rats.This work paves an avenue for the development of novel dual-mode delivery systems for effective bone regeneration.

A Ni/Ni_(2)P heterostructure in modified porous carbon separator for boosting polysulfide catalytic conversion

The intrinsic sluggish conversion kinetics and severe shuttle effect in lithium-sulfur(Li-S)batteries are responsible for their poor reversible capacity and cycling longevity,which have greatly hindered their practical applications.To address these drawbacks,herein,we design and construct a heterostructured Ni/Ni_(2)P embedded in a mesoporous carbon nanosphere composite(Ni/Ni_(2)P-MCN)for boosting polysulfide catalytic conversion in Li-S batteries.The Ni/Ni_(2)PMCN-modified separator could not only prevent the shuttle effect significantly through abundant chemical adsorptive sites,but also demonstrate superior catalytic reactivities for the conversion of polysulfides.More importantly,the conductive carbon matrix with an exposed mesoporous structure can serve as an effective physical barrier to accommodate deposited insoluble Li_(2)S.Consequently,the cells with the Ni/Ni_(2)P-MCN-modified separator exhibit greatly boosted rate capability(431 mA h g^(-1) at 5 C)and cycling stability(a capacity decay of 0.031% per cycle after 1500 cycles).Even at an enhanced sulfur loading of 4.2 mg cm^(-2),a stable and superior areal capacity(about 3.5 mA h cm^(-2))has been demonstrated.We envision that the unique Ni/Ni_(2)P heterostructure in the porous carbon matrix could offer great potential for highperformance and sustained energy storage devices.

Confined structure regulations of molybdenum oxides for efficient tumor photothermal therapy

Molybdenum oxide nanoparticles(NPs) with tunable plasmonic resonance in the near-infrared region display superior semiconducting features and photothermal properties, which are highly related to the crystalline and defective structures such as oxygen deficiencies. However,fundamental understanding on the structure-function relationship between crystalline/defective structures and photothermal properties is still unclear. To address this, herein,we have developed an "in-situ confined oxidation-reduction"strategy to regulate the defect features of molybdenum oxide NPs in the dual-mesoporous silica nanoreactor. Especially, the effects of crystalline structure/oxygen defects of molybdenum oxides on the photothermal performances were investigated by facilely tuning the amount of molybdenum resource and the reduction temperature. As a photothermal nanoagent, the optimal defective molybdenum oxide NPs encapsulated in PEGylated porous silica nanoreactor(designated as MoO_(3)@PPSNs) exhibit excellent biological stability and strong localized surface plasmon resonance effect in nearinfrared absorption range with the highest photothermal conversion efficiency up to 78.7% under 808 nm laser irradiation. More importantly, the remarkable photothermal effects of MoO_(3)@PPSNs were comprehensively demonstrated both in vitro and in vivo. Consequently, we envision that the plasmonic MoO_(3)NPs in a biocompatible porous silica nanoreactor could be used as an efficient photothermal therapy agent for photothermal ablation of tumors.

Understanding on the Surfactants Engineered Morphology Evolution of Block Copolymer Particles and Their Precise Mesoporous Silica Replicas

Surfactant-directed block copolymer(BCP) particles have gained intensive attention owing to their attractive morphologies and ordered domains. However, their controllable fabrication suffers several limitations including complex design and synthesis of multiple surfactant systems, limited choices of block copolymers, and time-consuming post-processes, etc. Herein, a surfactant size-dependent phase separation route is proposed to precisely manipulate the architectures of the anionic block copolymer particles in the binary co-assembly system of BCP and surfactants. In the system of polystyrene block polyacrylic acid (PS-b-PAA) and quaternary ammonium surfactants, it is verified that facile control on the ordered phase separation structures and morphologies of BCP particles can be achieved via simply varying the alkyl lengths of the surfactants. The cationic surfactants are demonstrated participating in the fabrication of the internal structures of BCP particles. Especially, it is found that the cationic surfactants are integrate into the anionic polyacrylic acid(PAA) domain of BCP particles of PS-b-PAA to influence the volume fraction of PAA blocks, so that varied architectures of BCP particles are constructed. Based on these understandings, spherical or ellipsoidal BCP particles are obtained as expected, as well as their precisely inorganic mesoporous silica replicas through the block copolymer nanoparticle replicating route. More interestingly, the ellipsoidal mesoporous silica exhibits higher cellular internalization capability due to its lower energy expenditure during the internalization process, which presents promising potentials in biomedical applications, especially for high-efficient drug delivery systems. These findings may provide valuable insights into the confinement assembly of anionic block copolymers and the creation of special nanocarriers for high-efficiency biomacromolecule delivery in the biomedical community.

Cooperative organizations of small molecular surfactants and amphiphilic block copolymers:Roles of surfactants in the formation of binary co-assemblies

The construction of highly ordered organizations through self-assembly is one of the most popular phenomena both in natural and artificial environments.Amphiphilic molecules are the most commonly used building blocks for the self-assembly,which are conventionally known as amphiphilic low molecular weight surfactants with polar heads and nonpolar tails,or amphiphilic block copolymers(BCPs)consisting of covalently bonded hydrophilic and hydrophobic block chains.Compared with single surfactant self-assembly system,binary amphiphiles co-assembly systems composing of both small mass surfactants and amphiphilic BCPs feature high flexibilities and versatilities in materials designing and structure regulation,ascribing to the vast possibilities of intermolecular interactions within the systems and facile component modulations during the assembly processes.The amphiphilic features of the two kinds of molecules endow them with similar self-assembly behaviors,while the unique and distinct characters of each kind of amphiphiles lead to various complex but highly diversified co-assembly systems.According to the roles of the surfactant played in the co-assembly system,in this review,we summarize the binary coassembly systems from three distinct types:1)the co-micellization system in which the surfactants are added into the BCPs assemblies as a self-assembly assistant;2)the co-emulsification system in which the surfactants work as an emulsion stabilizer to assist and confine the assembly of BCPs in 3D geometries;3)the co-templating system where the individual micelles of both surfactant and BCPs are hierarchically arranged and distributed to guide the formation of hierarchical nanomaterials.Following this,the major potential applications of the nanomaterials synthesized from the binary amphiphiles in biological field are described.Finally,we shortly discuss the current challenges and future perspectives of the binary amphiphiles selfassembly systems.