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Designing efficient, inexpensive, and stable photocatalysts to degrade organic pollutants and antibiotics has become an effective way for environmental remediation. In this work, we successfully performed in situ growth of CdS QDs on the surface of elliptical BiVO4 to try to show the advantage of the binary heterojuncted photocatalyst (BVO@CdS) for the photocatalytic degradation of tetracycline (TC). The In situ growth of CdS QDs can provide a large number of reactive sites and also generate a larger contact area with BiVO4. In addition, compared with mechanical composite materials, in situ growth can significantly reduce the energy barrier at the interface between BiVO4 and CdS, providing more channels for the separation and migration of photogenerated charge carriers, and further improving reaction activity. As a result, BVO@CdS-0.05 shows the best degradation efficiency, with a degradation rate of 88% after 30 min under visible light. The TC photodegradation follows a pseudo-second-order reaction with a dynamic constant of 0.472 min−1, which is 6.47 times that of pure BiVO4, 7.24 times that of pure CdS QDs and 2 times that of the mechanical composite. The degradation rate of BVO@CdS-0.05 decreases to 77.8% with a retention rate of 88.5% after four cycles, demonstrating excellent stability. Through liquid chromatography-mass spectrometry (LC-MS) analysis, two possible pathways for TC degradation are proposed. Through free radical capture experiments, electron spin resonance measurements, and photoelectrochemical comprehensive analysis, it is confirmed that BVO@CdS composites have constructed an efficient Z-scheme heterojunction via in situ growth, thereby highly enhancing the separation and transport efficiency of charge carriers. [ABSTRACT FROM AUTHOR]

Excessive emission of CO2 into the atmosphere has severely impacted the global ecological environment. Converting CO2 into valuable chemicals and fuels is of great significance for sustainable development. However, low activity and undesirable selectivity often result from the inherent inertness of CO2. Herein, K- or/and Zn-modified Fe-based catalysts were prepared by an incipient-wetness impregnation method for CO2 hydrogenation via a cascade reaction. The results indicate that K species exist as K2O while Zn species exist as ZnFe2O4. In the CO2 hydrogenation pathway, K2O facilitates the adsorption of CO2 and restrains the adsorption of H2, accelerating the transformation of CO2 into C2–C4 olefins rather than paraffins while Zn species promote the dispersion of Fe species, leading to improved activity. Synergistically, a K- and Zn-modified Fe-based catalyst (2Zn–10K–Fe/Al) shows excellent catalytic CO2 hydrogenation activity, achieving a CO2 conversion of 77% which is 1.8 times that (42%) of the unmodified Fe-based catalyst (Fe/Al). Our catalyst also shows a significantly promoted selectivity to C2–C4 olefins of 17% in comparison with the Fe/Al catalyst (0%). It is envisioned that such a binary effect of elements might contribute to the low-cost and industrial production of Fe-based catalysts for selective CO2 conversion. [ABSTRACT FROM AUTHOR]

The catalytic oxidative desulfurization (ODS) technique is able to remove sulfur compounds from fuels, conducive to achieving deep desulfurization for the good of the ecological environment. Ti-based metal–organic frameworks (Ti-MOFs) possessing good affinity to organic reactants and considerable numbers of Ti active sites are promising catalysts for ODS. However, current Ti-MOFs suffer from severe diffusion limitations caused by the size mismatch between sole micropores and bulky sulfur compounds, leading to poor ODS performance. Here, a facile method of intraparticle ripening without any additive is developed to obtain hierarchically meso–microporous Ti-MIL-125 single crystals (Meso-Ti-MIL-125) for the first time. Such Meso-Ti-MIL-125 shows a BET surface area of 1401 m2 g−1 and a mesoporous volume that is 1.7 times as high as that of the conventional Ti-MIL-125. Our novel Meso-Ti-MIL-125 exhibits excellent catalytic performance in the ODS of a series of bulky thiophenic sulfur compounds, completely removing benzothiophene (BT), dibenzothiophene (DBT), and 4,6-dimethyldibenzothiophene (DMDBT) from model fuels, which is, respectively, 2.4 times, 1.5 times, and 6.7 times higher than the removal achieved with conventional Ti-MIL-125. Such a facile synthetic strategy is envisioned to be applied in many kinds of crystalline materials, such as zeolites, for industrial production. [ABSTRACT FROM AUTHOR]

Coupling polymer and ionic liquids with electrodes for catalysis is a promising tool for optimization of electrocatalytic CO2 reduction reaction (CO2RR). Here, block copolymer ionic liquids BCPILs were synthesized via controlled radical polymerization and nucleophilic post-substitution to introduce imidazole moieties. We show that, thanks to these PIL functionalities, the BCPIL/Re@HPC/GDL electrode can keep the selectivity toward CO when a higher amount of water is present in the electrolyte than the raw Re@HPC/GDL system. Our results help to understand the development of solid-state ionic liquids for enhanced CO2RR in water-based electrolyte. [ABSTRACT FROM AUTHOR]

For the first time, we demonstrate a Ti-MOF (Ti-metal organic framework) single-crystal featuring an intracrystal macro–microporous hierarchy (Hier-NTU-9) by a vapor-assisted polymer-templated method. This Hier-NTU-9 possesses macropores (100–1000 nm) derived from polymer templates and enhanced transport ability of bulky molecules, exhibiting almost double the desulfurization activity compared to the conventional NTU-9. [ABSTRACT FROM AUTHOR]

Photorefining of biomass and its derivatives to value-added chemicals is an alternative solution to address the global energy shortage and environmental issues. Herein, efficient and selective oxidation of 5-hydroxymethylfurfural (HMF, 91.1% conversion) to 2,5-diformylfuran (DFF, 99.4% selectivity) is demonstrated by visible light-driven photocatalysis over cocatalyst-free ZnIn2S4 nanosheets with crystal facet engineering. The spatial accumulation of photogenerated electrons and holes on the (110) and (102) crystal facets triggers a two-electron oxygen reduction reaction (2e-ORR) for H2O2 generation and HMF oxidation into DFF, respectively. The severe attenuation of photostability is caused by the irreversible photocorrosion of Zn–S with the formation of Zn–O chemical bonds by the formation of ˙OH from the in situ decomposition of H2O2. Spontaneous substitution of oxygen with sulfur has been proven to efficiently improve the photostability of ZnIn2S4. This present work provides insights into improving the durability of ZnIn2S4 and sheds new light on biomass valorization via photorefinery. [ABSTRACT FROM AUTHOR]

Cs3Bi2Br9 decorated with crystalline–amorphous Pd nanocubes as cocatalysts is reported to photocatalytically coproduce ca. 1400 μmol h−1 g−1 of H2 and benzaldehyde from the selective benzyl alcohol oxidation. This route offers an alternative for photocatalytic H2 generation using metal halide perovskites under mild conditions. [ABSTRACT FROM AUTHOR]

Recently, Se cathodes have caught growing attention owing to their higher electronic conductivity, better compatibility with the carbonate electrolyte and comparable theoretical volumetric capacity to S cathodes. However, large volume variation, shuttle effect and sluggish redox kinetics have hindered the development of Li–Se batteries. Herein, we report chain-mail Co@C nanoparticles (Co@C NPs) embedded in macro-meso-microporous carbon nanofibers (CPCFs) with the characteristics of generalized Murray's law as a flexible Se host for advanced Li–Se batteries. The chain-mail Co@C structure protects Co from both active species and electrolyte, and then strengthens the adsorption-catalytic functions for active Se and Li2Se, thus improving the one-step solid-phase redox. In addition, the hierarchical porous structure enhances mass transfer and relieves volume expansion. Accordingly, the Se@CPCFs cathode demonstrates a high capacity of ∼500 mA h g−1 at 0.2C (1C = 675 mA g−1) after 500 cycles and exhibits high-capacity retention of 97.4%, 97.6%, and 99.1% between 1 and 100, 100 and 300, and 300 and 500 cycles. An excellent rate capability at 10C with a reversible specific capacity of 438 mA h g−1 is also realized. This work pioneered the utilization of chain-mail metal NPs as electrocatalysts to accelerate the solid-phase redox kinetics of Se cathodes for advanced Li–Se batteries. [ABSTRACT FROM AUTHOR]

Herein, we have demonstrated synergistic zinc doping and defect engineering toward MoS2 nanosheet arrays assembled on carbon cloth (CC) by a one-pot hydrothermal approach for the first time, which are employed directly as a cathode for the hydrogen evolution reaction (HER). In our strategy, simultaneously doping sufficient Zn atoms and introducing a defect-rich structure into a MoS2 nanosheet can synergistically increase active sites. Additionally, the assembly of such nanosheets on CC can achieve lower charge-transfer resistance for the highly efficient HER. [ABSTRACT FROM AUTHOR]

As an extraordinarily lightweight and porous functional nanomaterial family, aerogels have attracted considerable interest in academia and industry in recent decades. Despite the application scopes, the modest mechanical durability of aerogels makes their processing and operation challenging, in particular, for situations demanding intricate physical structures. "Bottom-up" additive manufacturing technology has the potential to address this drawback. Indeed, since the first report of 3D printed aerogels in 2015, a new interdisciplinary research area combining aerogel and printing technology has emerged to push the boundaries of structure and performance, further broadening their application scope. This review summarizes the state-of-the-art of printed aerogels and presents a comprehensive view of their developments in the past 5 years, and highlights the key near- and mid-term challenges. [ABSTRACT FROM AUTHOR]

Eggshells are essential for the reproduction of birds since the optical properties of shells may have an impact on biological functions such as heating and UV protection, recognition by parents or camouflage. Whereas ultraviolet reflection by some bird eggshells has been recently described, its physical origin remains poorly understood. In this study, we identified a porous structure in eggshells. Using Mie scattering modelling, we found it was most likely responsible for reflectance peaks (intensities of ca. 20–50%) observed in the near-UV range. These peaks were observed by spectrophotometric measurements from eggshells of several breeds of hen, one breed of duck and one breed of quail. This optical response was interpreted in terms of the distinct visual perception of hens and humans: eggshells appearing achromatic for humans proved to be chromatic for hens. Fluorescence emission from these eggs was also characterised and attributed to the presence of protoporphyrin IX and biliverdin IXα in the shells. Electron microscopy observations revealed the presence of pores within the so-called calcified shell part (i.e., at depths between ca. 20 μm and ca. 240 μm from the eggshell's outer surface). Mercury intrusion porosimetry allowed us to quantify the pore size distribution. Simulations of the UV response of this porous structure using Mie scattering theory as well as an effective approach accounting for multiple scattering indicate that these pores are responsible for the backscattering peaks observed in the UV range, in the case of beige hen eggshells. Due to the similarities between the pore size distributions observed for beige hen eggshells and other investigated poultry eggshells, we expect Mie backscattering to be the origin of the UV response of the eggshells of many other bird species. [ABSTRACT FROM AUTHOR]

The rapid development of the Internet of Things (IoT)-enabled applications and connected automation are increasingly making sensing technologies the heart of future intelligent systems. The potential applications have wide-ranging implications, from industrial manufacturing and chemical process control to agriculture and nature conservation, and even to personal health monitoring, smart cities, and national defence. Devices that can detect trace amounts of analyte gases represent the most ubiquitous of these sensor platforms. In particular, the advent of nanostructured organic and inorganic materials has significantly transformed this field. Highly sensitive, selective, and portable sensing devices are now possible due to the large surface to volume ratios, favorable transport properties and tunable surface chemistry of the sensing materials. Here, we present a review on the recent development of printed gas sensors. We first introduce the state-of-the-art printing techniques, and then describe a variety of gas sensing materials including metal oxides, conducting polymers, carbon nanotubes and two-dimensional (2D) materials. Particular emphases are given to the working principles of the printing techniques and sensing mechanisms of the different material systems. Strategies that can improve sensor performance via materials design and device fabrication are discussed. Finally, we summarize the current challenges and present our perspectives in opportunities in the future development of printed gas sensors. [ABSTRACT FROM AUTHOR]

Vanadium oxides are a class of promising anode candidates for sodium-ion batteries (SIBs) with high theoretical capacity and low cost. However, their practical application has been impeded by the low electronic conductivity, sluggish ionic transport and large volume change upon sodiation. Herein, a novel, high-performance anode for SIBs based on an oxygen-deficient vanadium oxide (VO/V2O3) heterostructure embedded in porous nitrogen-doped carbon (denoted as VNC) derived by a very simple and localized phase transition from a vanadium glycolate precursor has been demonstrated. The strong synergy of the hierarchically porous framework, VO/V2O3 phase heterojunctions with oxygen vacancy defects, and interfacial coupling with N-doped carbon (NC) efficiently promotes the electron/ion transport and alleviates the volume change during the sodiation/de-sodiation process. Electrochemical evaluation reveals that this novel VNC anode material manifests high sodium-ion storage capability and stability. Ex situ X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) analyses show that (a portion of) the vanadium oxides can be converted into vanadium metal and sodium oxides. First-principles density functional theory (DFT) calculations reveal that coupling with NC effectively enhances the interfacial interactions and charge transfer between vanadium oxides and carbon, as well as the conversion reaction kinetics during sodiation/desodiation. The present work offers a viable strategy for the rational design and exploration of novel heterostructure composite electrodes for a wide array of beyond-lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries with high theoretical specific capacity are quite promising in energy storage systems. The application of lithium–sulfur batteries however has mainly been hampered by the severe shuttle effect of polysulfides during the charging/discharging process. Here, we report the in situ self-assembling of ultra-thin flexible polyaniline layer decorated manganese dioxide nanoparticles (PANI–MnO2) to form a three-dimensional hierarchically porous network as a sulfur host for lithium–sulfur batteries. The hierarchically porous PANI–MnO2 network not only provides a porous structure to alleviate the volume expansion, but also offers fast channels to accelerate the transfer of active species, electrons and ions to improve the redox reaction kinetics. The as-fabricated PANI–MnO2–S electrode thus demonstrates excellent electrochemical performance, with a stable capacity up to 1195 mA h g−1 at 0.5C after 100 cycles. In particular, the hierarchically porous PANI–MnO2 network employs an extraordinary chemical process for polysulfides to form active thiosulfates, which are further converted into Li2S. This significantly suppresses the shuttle effect, thus providing the possibility for fast charging. As a result, the PANI–MnO2–S electrode exhibits a discharge capacity of 640 mA h g−1 at 2C after 500 cycles. Even at a high sulfur loading of 4.0 mg cm−2, a stable areal capacity of ∼3.12 mA h cm−2 is achieved at 1C after 200 cycles. [ABSTRACT FROM AUTHOR]

Two modified TiO2 nanofluids were developed, with either hydrophobic or hydrophilic properties. The hydrophobic TiO2 nanofluid, embedded in an organo-silyl salt, could be transformed into a hydrophilic TiO2 nanofluid by exchange of the chloride with an organo-sulphonate ion. Both modified TiO2 nanofluids exhibited high fluidity, thermal stability and photoactivity. [ABSTRACT FROM AUTHOR]

Hydrogen therapy is an emerging and promising strategy for treatment of inflammation-related diseases owing to the excellent bio-safety of hydrogen molecules (H2), but is facing a challenge that the H2 concentration at the local disease site is hardly accumulated because of its high diffusibility and low solubility, limiting the efficacy of hydrogen therapy. Herein, we propose a nanomedicine strategy of imaging-guided tumour-targeted delivery and tumour microenvironment-triggered release of H2 to address this issue, and develop a kind of biocompatible carboxymethyl cellulose (CMC)-coated/stabilized Fe (Fe@CMC) nanoparticle with photoacoustic imaging (PAI), tumour targeting and acid responsive hydrogen release properties for cancer therapy. The Fe@CMC nanoparticles have demonstrated high intratumoural accumulation capability, high acid responsiveness, excellent PAI performance, selective cancer-killing effect and high bio-safety in vitro and in vivo. Effective inhibition of tumour growth is achieved by intravenous injection of the Fe@CMC nanoparticles, and the selective anti-cancer mechanism of Fe@CMC is discovered to be originated from the energy metabolism homeostasis regulatory function of the released H2. The proposed nanomedicine-mediated hydrogen therapy strategy will open a new window for precise, high-efficacy and safe cancer treatment. [ABSTRACT FROM AUTHOR]

Sodium–selenium (Na–Se) batteries are a promising substitute for traditional Li-ion batteries due to their high theoretical volumetric capacity (∼3260 mA h cm−3). However, shuttle effects and large volume changes still limit their practical applications. Herein, we embed Se clusters in nitrogen-doped hierarchically radial-structured microporous carbon (N-HRMC) derived from a zinc-glutamate metal–organic framework (MOF) for advanced sodium storage. In this carbon-based composite, the micropores and the C–Se and C–O–Se bonds in N-HRMC effectively confine the Se clusters and Na2Se during the discharge–charge process. The nitrogen doping in N-HRMC strongly enhances the electrical conductivity of Se and chemical adsorption on Na2Se. In particular, density functional theory (DFT) calculations demonstrate that pyridinic-N atoms provide much more chemical adsorption of Na2Se than graphitic-N and pyrrolic-N atoms. Consequently, the cathode with Se clusters embedded in N-HRMC deliver a capacity of 612 mA h g−1 after 200 cycles at 0.2C, with cycling stability for ＞500 cycles and a capacity retention of ∼100% from the 20th cycle at 0.5C, representing one of the best reported results for Na–Se batteries. Our work here suggests that embedding Se clusters in nitrogen-doped hierarchically structured microporous carbon systems presents an attractive strategy to enhance the capacity and rate capability of Na–Se batteries. [ABSTRACT FROM AUTHOR]

A porous TiO2/BaTiO3 heterostructure composite has been developed as a polysulfide mediator for lithium–sulfur batteries. Superior electrochemical performance has been achieved, mainly attributed to the synergy of TiO2 and BaTiO3 with dual affinity to polysulfides from chemical and ferroelectric-induced polarization effects, and enhanced redox kinetics propelled by the TiO2/BaTiO3 heterojunctions. [ABSTRACT FROM AUTHOR]

Our whole-cell biocatalyst with a polydopamine nanocoating shows high catalytic activity (5 times better productivity than the native cell) and reusability (84% of the initial yield after 5 batches, 8 times higher than the native cell) in asymmetric reduction. It also integrates with titania, silica, and magnetic nanoparticles for multi-functionalization. [ABSTRACT FROM AUTHOR]

A new H2O2-responsive nanomedicine for CO therapy is constructed by effectively encapsulating the hydrophobic manganese carbonyl prodrug into an advanced hollow mesoporous silica nanoparticle carrier to realize the intratumoral H2O2-triggered release of CO and selective killing of tumour cells rather than normal cells, exhibiting high in vitro and in vivo efficacies of CO therapy. [ABSTRACT FROM AUTHOR]

Owing to their immense potential in energy conversion and storage, catalysis, photocatalysis, adsorption, separation and life science applications, significant interest has been devoted to the design and synthesis of hierarchically porous materials. The hierarchy of materials on porosity, structural, morphological, and component levels is key for high performance in all kinds of applications. Synthesis and applications of hierarchically structured porous materials have become a rapidly evolving field of current interest. A large series of synthesis methods have been developed. This review addresses recent advances made in studies of this topic. After identifying the advantages and problems of natural hierarchically porous materials, synthetic hierarchically porous materials are presented. The synthesis strategies used to prepare hierarchically porous materials are first introduced and the features of synthesis and the resulting structures are presented using a series of examples. These involve templating methods (surfactant templating, nanocasting, macroporous polymer templating, colloidal crystal templating and bioinspired process, i.e. biotemplating), conventional techniques (supercritical fluids, emulsion, freeze-drying, breath figures, selective leaching, phase separation, zeolitization process, and replication) and basic methods (sol–gel controlling and post-treatment), as well as self-formation phenomenon of porous hierarchy. A series of detailed examples are given to show methods for the synthesis of hierarchically porous structures with various chemical compositions (dual porosities: micro–micropores, micro–mesopores, micro–macropores, meso–mesopores, meso–macropores, multiple porosities: micro–meso–macropores and meso–meso–macropores). We hope that this review will be helpful for those entering the field and also for those in the field who want quick access to helpful reference information about the synthesis of new hierarchically porous materials and methods to control their structure and morphology. [ABSTRACT FROM AUTHOR]

Surface composition control plays a crucial role in electrocatalytic reactions for Pt-based bimetallic materials. However, strategies for controlling their surface composition always require extreme conditions including the use of harsh agents, the need for high temperatures, and the necessity of complex procedures. Here we develop a photo-assisted method to fabricate Au@PtAu core–shell nanoparticles (NPs) with well-tuned surface composition at ambient temperatures. It was found that their surface composition can be continuously regulated by the addition amount of HAuCl4 under photo-irradiation. By incorporating Au atoms, the synthesized Au@PtAu NPs show significantly improved properties for methanol electro-oxidation, owing to the reduced CO formation and the weakened binding strength of CO on Pt. The catalytic activity and durability vary with the relative active surface area of Pt or Au (PtSurf. or AuSurf.), and the optimal PtSurf. was found to be ∼64% (AuSurf.∼36%). The present work highlights the “photo-assisted method” as a green and effective method to synthesize advanced materials with optimized functional properties. [ABSTRACT FROM AUTHOR]

A facile high-viscosity-solvent method is presented to synthesize PtPd bimetallic nanocrystals highly dispersed in different mesostructures (2D and 3D structures), porosities (large and small pore sizes), and compositions (silica and carbon). Further, highly catalytic activity, stability and durability of the nanometals have been proven in different catalytic reactions. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are receiving significant attention as an alternative power system for advanced electronic devices because of their high theoretical capacity and energy density. In this work, we have designed manganese dioxide (MnO2) nanosheet functionalized sulfur@poly(3,4-ethylenedioxythiophene) core–shell nanospheres (S@PEDOT/MnO2) for high performance lithium–sulfur (Li–S) batteries. A PEDOT layer is used to address the low electrical conductivity of sulfur and acts as a protective layer to prevent dissolution of polysulfides. The MnO2 nanosheets functionalized on PEDOT further provide a high active contact area to enhance the wettability of the electrode materials with electrolytes and further interlink the polymer chains to improve the conductivity and stability of the composite. As a result, S@PEDOT/MnO2 exhibits an improved capacity of 827 mA h g−1 after 200 cycles at 0.2C (1C = 1673 mA g−1) and a further ∼50% enhancement compared to S@PEDOT (551 mA h g−1) without MnO2 functionalization. In particular, the discharge capacity of S@PEDOT/MnO2 is 545 mA h g−1 after 200 cycles at 0.5C. Our demonstration here indicates that the functionalization of inorganic nanostructures on conducting polymer coated sulfur nanoparticles is an effective strategy to improve the electrochemical cycling performance and stability of sulfur cathodes for Li–S batteries. [ABSTRACT FROM AUTHOR]

Over the last decade, significant effort has been devoted to the applications of hierarchically structured porous materials owing to their outstanding properties such as high surface area, excellent accessibility to active sites, and enhanced mass transport and diffusion. The hierarchy of porosity, structural, morphological and component levels in these materials is key for their high performance in all kinds of applications. The introduction of hierarchical porosity into materials has led to a significant improvement in the performance of materials. Herein, recent progress in the applications of hierarchically structured porous materials from energy conversion and storage, catalysis, photocatalysis, adsorption, separation, and sensing to biomedicine is reviewed. Their potential future applications are also highlighted. We particularly dwell on the relationship between hierarchically porous structures and properties, with examples of each type of hierarchically structured porous material according to its chemical composition and physical characteristics. The present review aims to open up a new avenue to guide the readers to quickly obtain in-depth knowledge of applications of hierarchically porous materials and to have a good idea about selecting and designing suitable hierarchically porous materials for a specific application. In addition to focusing on the applications of hierarchically porous materials, this comprehensive review could stimulate researchers to synthesize new advanced hierarchically porous solids. [ABSTRACT FROM AUTHOR]