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Since the discovery in 2000, conversion-type materials have emerged as a promising negative-electrode candidate for next-generation batteries with high capacity and tunable voltage, limited by low reversibility and severe voltage hysteresis. Heterogeneous construction stands out as a cost-effective and efficient approach to reducing reaction barriers and enhancing energy density. However, the second term introduced by conventional heterostructure inevitably complicates the electrochemical analysis and poses great challenges to harvesting systematic insights and theoretical guidance. A model cell is designed and established herein for the conversion reactions between Na and TM SA -SnO 2 , where TM SA -SnO 2 represents single atom modification of eight different 3d transition elements (V, Cr, Mn, Fe, Co, Ni, Cu or Zn). Such a model unit fundamentally eliminates the interference from the second phase and thus enables independent exploration of activation manifestations of the heterogeneous architecture. For the first time, a thermodynamically dependent catalytic effect is proposed and verified through statistical data analysis. The mechanism behind the unveiled catalytic effect is further elucidated by which the active d orbitals of transition metals weaken the surface covalent bonds and lower the reaction barriers. This research provides both theoretical insights and practical demonstrations of the advanced heterogeneous electrodes., (© 2024 Wiley-VCH GmbH.)

Spin state is often regarded as the crucial valve to release the reactivity of energy-related catalysts, yet it is also challenging to precisely manipulate, especially for the active center ions occupied at the specific geometric sites. Herein, a π-π type orbital coupling of 3d (Co)-2p (O)-4f (Ce) was employed to regulate the spin state of octahedral cobalt sites (Co Oh ) in the composite of Co 3 O 4 /CeO 2 . More specifically, the equivalent high-spin ratio of Co Oh can reach to 54.7 % via tuning the CeO 2 content, thereby triggering the average e g filling (1.094) close to the theoretical optimum value. The corresponding catalyst exhibits a superior water oxidation performance with an overpotential of 251 mV at 10 mA cm -2 , rivaling most cobalt-based oxides state-of-the-art. The π-π type coupling corroborated by the matched energy levels between Ce t 1u /t 2u -O and Co Oh t 2g -O π type bond in the calculated crystal orbital Hamilton population and partial density of states profiles, stimulates a π-donation between O 2p and π-symmetric Ce 4f yz 2 orbital, consequently facilitating the electrons hopping from t 2g to e g orbital of Co Oh . This work offers an in-depth insight into understanding the 4f and 3d orbital coupling for spin state optimization in composite oxides., (© 2024 Wiley-VCH GmbH.)

High entropy materials offer almost unlimited catalytic possibilities due to their variable composition, unique structure, and excellent electrocatalytic performance. However, due to the strong tendency of nanoparticles to coarsen and agglomerate, it is still a challenge to synthesize nanoparticles using simple methods to precisely control the morphology and size of the nanoparticles in large quantities, and their large-scale application is limited by high costs and low yields. Herein, a series of high-entropy oxides (HEOs) nanoparticles with high-density and ultrasmall size (<5 nm) loaded on carbon nanosheets with large quantities are prepared by Joule-heating treatment of gel precursors in a short period of time (≈60 s). Among them, the prepared (FeCoNiRuMn) 3 O 4-x catalyst shows the best electrocatalytic activity for oxygen evolution reaction, with low overpotentials (230 mV @10 mA cm -2 , 270 mV @100 mA cm -2 ), small Tafel slope (39.4 mV dec -1 ), and excellent stability without significant decay at 100 mA cm -2 after 100 h. The excellent performance of (FeCoNiRuMn) 3 O 4-x can be attributed to the synergistic effect of multiple elements and the inherent structural stability of high entropy systems. This study provides a more comprehensive design idea for the preparation of efficient and stable high entropy catalysts., (© 2024 Wiley‐VCH GmbH.)

It is a pressing need to develop new energy materials to address the existing energy crisis. However, screening optimal targets out of thousands of material candidates remains a great challenge. Herein, an alternative concept for highly effective materials screening based on dual-atom salphen catalysis units, is proposed and validated. Such an approach simplifies the design of catalytic materials and reforms the trial-and-error experimental model into a building-blocks-assembly like process. First, density functional theory (DFT) calculations are performed on a series of potential catalysis units that are possible to synthesize. Then, machine learning (ML) is employed to define the structure-performance relationship and acquire chemical insights. Afterward, the projected catalysis units are integrated into covalent organic frameworks (COFs) to validate the concept Electrochemical tests confirming that Ni-SalphenCOF and Co-SalphenCOF are promising conductive agent-free oxygen evolution reaction (OER) catalysts. This work provides a fast-tracked strategy for the design and development of functional materials, which serves as a potentially workable framework for seamlessly integrating DFT calculations, ML, and experimental approaches., (© 2024 Wiley‐VCH GmbH.)

The interactions between the catalyst and support are widely used in many important catalytic reactions but the construction of strong interaction with definite microenvironments to understand the structure-activity relationship is still challenging. Here, strongly-interacted composites are prepared via selective exsolution of active NiSe 2 from the host matrix of NiFe 2 O 4 (S-NiSe 2 /NiFe 2 O 4 ) taking advantage of the differences of migration energy, in which the NiSe 2 possessed both high dispersion and small size. The characteristics of spatially resolved scanning transmission X-ray microscopy (STXM) coupled with analytical Mössbauer spectra for the surface and bulk electronic structures unveiled that this strongly interacted composite triggered more charge transfers from the NiSe 2 to the host of NiFe 2 O 4 while stabilizing the inherent atomic coordination of NiFe 2 O 4 . The obtained S-NiSe 2 /NiFe 2 O 4 exhibits overpotentials of 290 mV at 10 mA cm -2 for oxygen evolution reaction (OER). This strategy is general and can be extended to other supported catalysts, providing a powerful tool for modulating the catalytic performance of strongly-interacted composites., (© 2023 Wiley‐VCH GmbH.)

Anionic modification engineering is a crucial approach to develop highly efficient electrocatalysts for hydrogen evolution reaction. Herein, halogen elements (X = Cl, Br, and I)-modified Ru-based nanosheets (X-Ru/RuP 2 ) are designed by rapid and eco-friendly microwave-phosphide plasma approach within 60 s. Experimental and density functional theory calculations verify that the introduced halogen element, especially Br, can optimize the surface intermediates adsorption. Specially, the designed Br-Ru/RuP 2 favors the water dissociation and following hydrogen adsorption/desorption process. Then, the as-synthesized Br-Ru/RuP 2 exhibits low overpotential of 34 mV to reach 10 mA cm -2 coupled with small Tafel slope of 27 mV dec -1 in alkaline electrolyte with excellent long-term stability. Moreover, the electrocatalytic performances in acid and neutral media are also boosted via Br element modification. This work paves a novel way to regulate the electronic structure of Ru-based compounds, and then can boost the electrocatalytic kinetics., (© 2023 Wiley‐VCH GmbH.)

Metal single atoms (SAs) anchored in carbon support via coordinating with N atoms are efficient active sites to oxygen reduction reaction (ORR). However, rational design of single atom catalysts with highly exposed active sites is challenging and urgently desirable. Herein, an anion exchange strategy is presented to fabricate Fe-N 4 moieties anchored in hierarchical carbon nanoplates composed of hollow carbon spheres (Fe-SA/N-HCS). With the coordinating O atoms are substituted by N atoms, Fe SAs with Fe-O 4 configuration are transformed into the ones with Fe-N 4 configuration during the thermal activation process. Insights into the evolution of central atoms demonstrate that the SAs with specific coordination environment can be obtained by modulating in situ anion exchange process. The strategy produces a large quantity of electrochemical accessible site and high utilization rate of Fe-N 4 . Fe-SA/N-HCS shows excellent ORR electrocatalytic performance with half-wave potential of 0.91 V (vs. RHE) in 0.1 M KOH, and outstanding performance when used in rechargeable aqueous and flexible Zn-air batteries. The evolution pathway for SAs demonstrated in this work offers a novel strategy to design SACs with various coordination environment and enhanced electrocatalytic activity., (© 2023 Wiley-VCH GmbH.)

Phototheranostic agents have thrived as prominent tools for tumor luminescence imaging and therapies. Herein, a series of organic photosensitizers (PSs) with donor-acceptors (D-A) are elaborately designed and synthesized. In particular, PPR-2CN exhibits stable near infrared-I (NIR-I) emission, excellent free radicals generation and phototoxicity. Experimental analysis and calculations imply that a small singlet-triplet energy gap (ΔE S1-T1 ) and large spin-orbit coupling (SOC) constant boost the intersystem crossing (ISC), leading to type-I photodynamic therapy (PDT). Additionally, the specific glutamate (Glu) and glutathione (GSH) consumption abilities of PPR-2CN inhibit the intracellular biosynthesis of GSH, resulting in redox dyshomeostasis and GSH-depletion causing ferroptosis. This work first realizes that single component organic PS could be simultaneously used as a type-I photodynamic agent and metal-free ferroptosis inducer for NIR-I imaging-guided multimodal synergistic therapy., (© 2023 Wiley-VCH GmbH.)

The development of fast charging materials offers a viable solution for large-scale and sustainable energy storage needs. However, it remains a critical challenge to improve the electrical and ionic conductivity for better performance. Topological insulator (TI), a topological quantum material that has attracted worldwide attention, hosts unusual metallic surface states and consequent high carrier mobility. Nevertheless, its potential in promising high-rate charging capability has not been fully realized and explored. Herein, a novel Bi 2 Se 3 -ZnSe heterostructure as excellent fast charging material for Na + storage is reported. Ultrathin Bi 2 Se 3 nanoplates with rich TI metallic surfaces are introduced as an electronic platform inside the material, which greatly reduces the charge transfer resistance and improves the overall electrical conductivity. Meanwhile, the abundant crystalline interfaces between these two selenides promote Na + migration and provide additional active sites as well. As expected, the composite delivers the excellent high-rate performance of 360.5 mAh g -1 at 20 A g -1 and maintains its electrochemical stability of 318.4 mAh g -1 after 3000 long cycles, which is the record high for all reported selenide-based anodes. This work is anticipated to provide alternative strategies for further exploration of topological insulators and advanced heterostructures., (© 2023 Wiley-VCH GmbH.)

Oxygen vacancies-enriched black TiO 2 is one promising support for enhancing hydrogen evolution reaction (HER). Herein, oxygen vacancies enriched black TiO 2 supported sub-nanometer Pt clusters (Pt/TiO 2 -O V ) with metal support interactions is designed through solvent-free microwave and following low-temperature electroless approach for the first time. High-temperature and strong reductants are not required and then can avoid the aggregation of decorated Pt species. Experimental and theoretical calculation verify that the created oxygen vacancies and Pt clusters exhibit synergistic effects for optimizing the reaction kinetics. Based on it, Pt/TiO 2 -O V presents remarkable electrocatalytic performance with 18 mV to achieve 10 mA cm -2 coupled with small Tafel slope of 12 mV dec -1 . This work provides quick synthetic strategy for preparing black titanium dioxide based nanomaterials., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

NiOOH is considered as the most active intermediate during electrochemical oxidation reaction, however, it is hard to directly synthesize due to high oxidation energy. Herein, theoretical calculations predict that α-FeOOH enables a decline in formation energy and an improvement in stabilization of NiOOH in NiFe-based layered double hydroxide (LDH). Inspiringly, a composite composed of α-FeOOH and LDH is well-designed and successfully fabricated in hydrothermal treatment by adding extra Fe 3+ resource, and stable NiOOH is obtained by the following electro-oxidation method. Benefiting from strong electron-capturing capability of α-FeOOH, it efficiently promotes charge redistribution around the Ni/Fe sites and activates Ni atoms of LDH, verified by X-ray photoelectron spectra (XPS) and X-ray absorption spectra (XAS). The d-band center is optimized that balances the absorption and desorption energy, and thus Gibbs free energy barrier is lowered dramatically toward oxygen evolution reaction (OER) and urea oxidation reaction (UOR), and finally showing an outstanding overpotential of 195 mV and a potential of 1.35 V at 10 mA cm -2 , respectively. This study provides a novel strategy to construct highly efficient catalysts via the introduction of a new phase for complex multiple-electron reactions., (© 2022 Wiley-VCH GmbH.)

The electronic structure of composites plays a critical role in photocatalytic conversion, whereas it is challenging to modulate the orbital for an efficient catalyst. Herein, we regulated the t 2g orbital occupancy state of Ti to realize efficient CO 2 conversion by adjusting the amount of photo-deposited Cu in the Cu/TiO 2 composite. For the optimal sample, considerable electrons transfer from the Cu d orbital to the Ti t 2g orbital, as proven by X-ray absorption spectroscopy. The Raman spectra results also corroborate the electron enrichment on the Ti t 2g orbital. Further theoretical calculations suggested that the orbital energy of the Ti 3d orbital in TiO 2 is declined, contributing to accepting Cu 3d electrons. As a result, the Cu/TiO 2 composite exhibited an extremely high selectivity of 95.9 % for CO, and the productivity was 15.27 μmol g -1  h -1 , which is almost 6 times that of the original TiO 2 . Our work provides a strategy for designing efficient photocatalysis as a function of orbital regulation., (© 2022 Wiley-VCH GmbH.)

Calcium-ion batteries (CIBs) are considered as promising alternatives in large-scale energy storage due to their divalent electron redox properties, low cost, and high volumetric/gravimetric capacity. However, the high charge density of Ca 2+ contributes to strong electrostatic interaction between divalent Ca 2+ and hosting lattice, leading to sluggish kinetics and poor rate performance. Here, in situ formed poly(anthraquinonyl sulfide) (PAQS)@CNT composite is reported as nonaqueous calcium-ion battery cathode. The enolization redox chemistry of organics has fast redox kinetics, and the introduction of carbon nanotube (CNT) accelerates electron transportation, which contributes to fast ionic diffusion. As the conductivity of the PAQS is enhanced by the increasing content of CNT, the voltage gap is significantly reduced. The PAQS@CNT electrode exhibits specific capacity (116 mAh g -1 at 0.05 A g -1 ), high rate capacity (60 mAh g -1 at 4 A g -1 ), and an initial capacity of 82 mAh g -1 at 1 A g -1 (83% capacity retention after 500 cycles). The electrochemical mechanism is proved to be that the PAQS undergoes reduction reaction of their carbonyl bond during discharge and becomes coordinated by Ca 2+ and Ca(TFSI) + species. Computational simulation also suggests that the construction of Ca 2+ and Ca(TFSI) + co-intercalation in the PAQS is the most reasonable pathway., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

The N6-methyladenosine (m 6 A) demethylase FTO plays an oncogenic role in acute myeloid leukemia (AML). Despite the promising recent progress for developing some small-molecule FTO inhibitors, the clinical potential remains limited due to mild biological function, toxic side effects and low sensitivity and/or specificity to leukemic stem cells (LSCs). Herein, FTO inhibitor-loaded GSH-bioimprinted nanocomposites (GNPIPP12MA) are developed that achieves targeting of the FTO/m 6 A pathway synergized GSH depletion for enhancing anti-leukemogenesis. GNPIPP12MA can selectively target leukemia blasts, especially LSCs, and induce ferroptosis by disrupting intracellular redox status. In addition, GNPIPP12MA increases global m 6 A RNA modification and decreases the transcript levels in LSCs. GNPIPP12MA augments the efficacy of the PD-L1 blockade by increasing the infiltration of cytotoxic T cells for enhanced anti-leukemia immunity. This study offers insights for a GSH-bioimprinted nanoplatform targeting m 6 A RNA methylation as a synergistic treatment strategy against cancer stem cells that may translate to clinical applications., (© 2022 Wiley-VCH GmbH.)

Constructing composite structures is an essential approach for obtaining multiple functionalities in a single entity. Available synthesis methods of the composites need to be urgently exploited; especially in situ construction. Here, a NiS/NiFe 2 O 4 composite through a local metal-S coordination at the interface is reported, which is derived from phase reconstruction in the highly defective matrix. X-ray absorption fine structure confirms that long-range order is broken via the local metal-S coordination and, by using electron energy loss spectroscopy, the introduction of NiS/NiFe 2 O 4 interfaces during the irradiation of plasma energy is identified. Density functional theory (DFT) calculations reveal that in situ phase reconfiguration is crucial for synergistically reducing energetic barriers and accelerating reaction kinetics toward catalyzing the oxygen evolution reaction (OER). As a result; it leads to an overpotential of 230 mV @10 mA cm -2 for the OER and a half-wave potential of 0.81 V for the oxygen reduction reaction (ORR); as well as an excellent zinc-air battery (ZAB) performance with a power density of 148.5 mW cm -2 . This work provides a new compositing strategy in terms of fast phase reconstruction of bifunctional catalysts., (© 2022 Wiley-VCH GmbH.)

Searching for Pt-like activity, stable and economic electrocatalysts that can function at various pH values for the hydrogen evolution reaction (HER) is under increasing interest for the scientific community as H 2 is a very promising energy carrier with great potential development value for renewable energy conversion. Herein, a unique self-supported heterostructure of RuO 2 -RuP 2 /Ru on the N, P co-doped carbon matrix (Ru-HMT-MP-7) is demonstrated, which is derived from HMT-based coordination polymers as superior pH-universal electrocatalysts. In the strategy, pyrolysis and phosphating processes are simultaneously proceeded that can produce the unique heterostructure containing three phases of RuO 2 , RuP 2, and Ru, at the same time the generated RuO 2 -RuP 2 /Ru can be highly dispersed on the self-assembly N, P co-doped carbon substrates. The resulting heterostructure Ru-HMT-MP-7 exhibits excellent activity superior to that of benchmark Pt/C with low overpotentials at 10 mA cm -2 (33 mV for 1.0 M KOH, 29 mV for 0.5 M H 2 SO 4 and 86 mV for 1.0 M PBS) and long-term electrocatalysis durability toward HER at various pH values. The rational construction strategy paves a novel avenue for obtaining superior pH-universal catalysts for electrochemical energy storage and conversion., (© 2022 Wiley-VCH GmbH.)

Direct ethanol fuel cells are among the most efficient and environmentally friendly energy-conversion devices and have been widely focused. The ethanol oxidation reaction (EOR) is a multielectron process with slow kinetics. The large amount of by-product generated by incomplete oxidation greatly reduces the efficiency of energy conversion through the EOR. In this study, a novel type of trimetallene called porous PdWM (M = Nb, Mo and Ta) is synthesized by a facile method. The mass activity (15.6 A mg Pd -1 ) and C1 selectivity (55.5%) of Pd 50 W 27 Nb 23 /C trimetallene, obtained after optimizing the compositions and proportions of porous PdWM, outperform those of commercial Pt/C (1.3 A mg Pt -1 , 5.9%), Pd/C (5.0 A mg Pd -1 , 7.2%), and Pd 97 W 3 /C bimetallene (9.5 A mg Pd -1 , 14.1%). The mechanism by which Pd 50 W 27 Nb 23 /C enhances the EOR performance is evaluated by in situ Fourier transform infrared spectroscopy and density functional theory calculations. It is found that W and Nb enhance the adsorption of CH 3 CH 2 OH and oxophilic high-valence Nb accelerates the subsequent oxidation of CO and CH x species. Moreover, Nb promotes the cleavage of CC bonds and increases the C1 selectivity. Pd 60 W 28 Mo 12 /C and Pd 64 W 27 Ta 9 /C trimetallene synthesized by the same method also exhibit excellent EOR performance., (© 2021 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Rechargeable zinc-ion batteries (ZIBs), which adopt mild aqueous electrolytes with high power density and safety, have received significant interest. As the most widely used cathode material for ZIBs, manganese-based oxide has poor rate performance owing to its low electronic conductivity and slow ion diffusion kinetics. In this study, using the synergistic regulation strategy of defect engineering and atomic composition tuning, a mesoporous Al 0.35 Mn 2.52 O 4 with an ultrahigh surface area (up to 82 m 2 g -1 ) is fabricated through Al substitution in the Mn 3 O 4 , followed by an Al-selective leaching process. During the entire process, numerous defects are obtained in the spinel structure by removing ≈30% of the Al cations. Al substitution can improve the material conductivity, while cation defects can weaken the electrostatic effect and promote ion diffusion ability. Therefore, the Al 0.35 Mn 2.52 O 4 cathode of ZIBs exhibits a high reversible capacity of 302 mAh g -1 at a current density of 100 mA g -1 . Furthermore, the reversible capacity remains at 147 mAh g -1 after 1000 cycles at a current density of 1500 mA g -1 . This synergistic regulation of atomic composition tuning and defect engineering provides a new perspective for improving the performance of electrode materials in ZIBs., (© 2021 Wiley-VCH GmbH.)

Improving proton conductivity and fabricating viable metal-organic frameworks (MOFs) based proton exchange membranes (PEMs) are central issues exploiting electrolyte MOFs. We aim to design multivariate flexibility synergistic strategy to achieve Flexible MOFs (FMOFs) with high conductivity at a wide range of humidity. In situ powder X-ray diffraction (PXRD) and temperature-dependent Fourier transform infrared spectra (FT-IR) prove the synergistic self-adaption between dynamic torsion of alkyl sulfonic acid and dynamic breathing of FMOF, forming a continuous hydrogen-bonding networks to maintain high conductivity. Based on the convincing proton conductivity, we construct a series of long-term durable MOF-based PEMs that serve as a bridge between MOF and fuel cell. Consequently, the membrane electrode assembly (MEA) of the flexible PMNS1-40 exhibits a maximum single-cell power density of 34.76 mW cm -2 and hopefully opens doors to evaluate the practical application of proton-conducting MOFs in direct methanol fuel cells., (© 2021 Wiley-VCH GmbH.)

A temperature-controlled cation-exchange approach is introduced to achieve a unique dual-exsolution in perovskite La 0.8 Fe 0.9 Co 0.1 O 3-δ where both CoFe alloy and Co metal are simultaneously exsolved from the parent perovskite, forming an alloy and metal co-decorated perovskite oxide. Mossbauer spectra show that cation exchange of Fe atoms in CoFe alloy and Co cations in the perovskite is the key to the co-existence of Co metal and CoFe alloy. The obtained composite exhibits an enhanced catalytic activity as Li-O 2 battery cathode catalysts with a specific discharge capacity of 6549.7 mAh g -1 and a cycling performance of 215 cycles without noticeable degradation. Calculations show that the combination of decorated CoFe alloy and Co metal synergistically modulated the discharge reaction pathway that improves the performance of Li-O 2 battery., (© 2021 Wiley-VCH GmbH.)

Both one-pot catalytic conversion of furfural (FAL) to isopropyl levulinate (PL) and carbonization of by-product (humins) for electromagnetic wave absorption are discussed, which provides inspiration that humins can be applied to electromagnetic wave absorption. In the former, phosphotungstic acid (PW) is employed as a homogeneous catalyst to convert FAL to PL via a tandem reaction in one pot, with the formation of a vast amount of humins. With FAL and various intermediates as substrates, it was found that humins was a polymerization product of FAL, furfuryl alcohol (FOL) and furfuryl ester (FE) with furan rings. In addition, the in situ attenuated total reflection infrared (ATR-IR) spectra also provided a basis for the proposed reaction route. In the latter, with the humins as raw material, P species and WO 3 doped nano-porous carbon (Humins-700) platform formed after high-temperature annealing is used for electromagnetic wave absorption and manifests desirable absorption performance. The minimum reflection loss (RL min ) value is -47.3 dB at 13.0 GHz with a thickness of 2.0 mm and the effective absorption bandwidth reaches 4.5 GHz (11.2-5.7 GHz)., (© 2021 Wiley-VCH GmbH.)

A designed structure which CoP nanoparticles (NPs) ingeniously connected with graphene-like carbon layer via in-situ generated interfacial oxygen-bridge chemical bonding was achieved by a mild phosphorization treatment. The results proved that the presence of phosphorus vacancies is a crucial factor enabling formation of Co-O-C bonds. The direct coupling of edge Co of CoP with the oxygen from functional groups on the carbon layer was proposed. As a catalyst for electrocatalytic water splitting, the manufactured Fe 2 O 3 @C@CoP core-shell structure manifested a low overpotential of 230 mV, a low Tafel slope of 55 mV dec -1 , and long-term stability. Density functional theory calculations verified that the Co-O-C bond played a critical role in decreasing the thermodynamic energy barrier of reaction rate-determining step for the oxygen evolution reaction (OER). This synthetic route might be extended to construct metal-O-C bonds in other transition metal phosphides (or selenides, sulfides)/carbon composites for highly efficient OER catalysts., (© 2021 Wiley-VCH GmbH.)

Exfoliation of non-layered (structurally) bulk materials at the nanoscale is challenging because of the strong chemical bonds in the lattice, as opposed to the weak van der Waals (vdW) interactions in layered materials. We propose a top-down method to exfoliate ϵ-MnO 2 nanosheets in a family of charge-ordered La 1-x AE x MnO 3 (AE=Ca, Sr, Ba) perovskites, taking advantage of the Jahn-Teller disproportionation effect of Mn 3+ and bond-strength differences. ϵ-MnO 2 crystallized into a nickel arsenide (NiAs) structure, with a thickness of 0.91 nm, displays thermal metastability and superior water oxidation activity compared to other manganese oxides. The exfoliation mechanism involves a synergistic proton-induced Mn 3+ disproportionation and structural reconstruction. The synthetic method could also be potentially extended to the exfoliation of other two-dimensional nanosheet materials with non-layered structures., (© 2020 Wiley-VCH GmbH.)

Hollow multishelled structures (HoMSs) provide a promising platform for fabricating photocatalysts, because the unique structure optimizes the effective surface and mass transport, showing enhanced light absorption, optimized mass transport and highly effective active sites exposed. Subsequently, the rational design on HoMS photocatalytsts is elaborated to boost the photocatalytic activity with efforts in all dimensions, from nanoscale to microscale. Breakthroughs in synthetic methodology of HoMSs have greatly evoked the prosperous photocatalytic researches for HoMSs since the developing of sequential templating approach in 2009. The dawn of HoMS photocatalyst is coming after revealing the temporal-spatial ordering property, which is also discussed in this paper with pioneer works demonstrating the greatly enhanced energy/mass transfer processes. Some insights into the key challenges and perspectives of HoMSs photocatalysts are also discussed. With the reviewed fate and future of HoMSs photocatalysts, hopefully new concepts and innovative works can be inspired to flourish this sun-rise field., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Herein we report two new TPE-based 3D MOFs, that is, Sr-ETTB and Co-ETTB (TPE=Tetraphenylethylene, H 8 ETTB=4',4''',4''''',4'''''''-(ethene-1,1,2,2-tetrayl)tetrakis(([1,1'-biphenyl]-3,5-dicarboxylic acid))). Through tailoring outer shell electron configurations of Sr II and Co II cations, the fluorescence intensity of the MOFs is tuned from high emission to complete non-emission. Sr-ETTB with strong blue fluorescence shows reversible fluorescence variations in response to pressure and temperature, which is directly related to the reversible deformation of the crystal structure. In addition, non-emissive Co-ETTB counterpart exhibits a turn-on fluorescent enhancement under the stimulation of analyte histidine. In the process, TPE-cored linkers in the MOFs are released through competitive coordination substitution and subsequently reassembled to perform aggregation-induced luminescence behavior originated from the organic linkers., (© 2020 Wiley-VCH GmbH.)

To boost the performance for various applications, a rational bottom-up design on materials is necessary. The defect engineering on nanoparticle at the atomic level can efficiently tune the electronic behavior, which offers great opportunities in enhancing the catalytic performance. In this paper, we optimized the surface oxygen vacancy concentration and created the lattice distortion in rare-earth-based perovskite oxide through gradient replacement of the B site with valence alternated element. The dual defects make the electron spin state transit from low spin state to high spin state, thus decreasing the charge transport resistance. Furthermore, assembly the modified nanoparticle subunits into the micro-sized hollow multishelled structures can provide porous shells, abundant interior space and effective contact, which enables an enhanced mass transfer and a shorter charge transport path. As a result, the systemic design in the electronic and nano-micro structures for catalyst has brought an excellent oxygen evolution performance., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Metal oxide hollow structures with large surface area, low density, and high loading capacity have received great attention for energy-related applications. Acting as oxygen-related catalysts, hollow-structured transition metal oxides offer low overpotential, fast reaction rate, and excellent stability. Herein, recent progress in the oxygen-related catalysis (e.g., oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and metal-air batteries) of hollow-structured transition metal oxides is discussed. Through a comprehensive outline of hollow-structured spinels, perovskites, rutiles, etc., a rational design strategy is provided for an enhanced oxygen-related catalysis performance from the viewpoint of crystal structures. Urgent challenges and further research directions are presented for hollow-structured transition metal oxides toward excellent oxygen-related catalysis., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Surface lattice oxygen in transition-metal oxides plays a vital role in catalytic processes. Mastering activation of surface lattice oxygen and identifying the activation mechanism are crucial for the development and design of advanced catalysts. A strategy is now developed to create a spinel Co 3 O 4  /perovskite La 0.3 Sr 0.7 CoO 3 interface by in situ reconstruction of the surface Sr enrichment region in perovskite LSC to activate surface lattice oxygen. XAS and XPS confirm that the regulated chemical interface optimizes the hybridized orbital between Co 3d and O 2p and triggers more electrons in oxygen site of LSC transferred into lattice of Co 3 O 4  , leading to more inactive O 2- transformed into active O 2-x . Furthermore, the activated Co 3 O 4 /LSC exhibits the best catalytic activities for CO oxidation, oxygen evolution, and oxygen reduction. This work would provide a fundamental understanding to explain the activation mechanism of surface oxygen sites., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Atomic metal species-based catalysts (AMCs) show remarkable possibilities in various catalytic reactions. The coordination configuration of the metal atoms has been widely recognized as the determining factor to the electronic structure and the catalytic activity. However, the synergistic effect between the adjacent layers of the multilayered AMCs is always neglected. We reported an atomic Co and Pt co-trapped carbon catalyst, which exhibits a ultrahigh activity for HER in the wide range of pH (η 10 =27 and 50 mV in acidic and alkaline media, respectively) with ultralow metal loadings (1.72 and 0.16 wt % for Co and Pt, respectively), which is much superior to the commercial Pt/C. Theoretical analysis reveals that the atomic metals on the inner graphitic layers significantly alter the electronic structure of the outmost layer, thus tailoring the HER activity. This finding arouses a re-thinking of the intrinsic activity origins of AMCs and suggests a new avenue in the structure design of AMCs., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Identifying the relationship between catalytic performance and material structure is crucial to establish the design principle for highly active catalysts. Deficiency in BO bond covalency induced by lattice distortion severely restricts the oxygen reduction reaction (ORR) performance for ABO 3 -type perovskite oxides. Herein, a rearrangement of hybridization mode for BO bond is used to tune the overlap of the electron cloud between B 3d and O 2p through A-stie doping with larger radius ions. The BO bond covalency is strengthened with a BOB bond angle recovered from intrinsic structural distortion. As a result, the adsorption and the reduction process for O 2 on the oxide surface can be promoted via shifting the O-2p band center toward the Fermi Level. Simultaneously, the spin electrons in the Mn 3d orbit become more parallel. It will lead to a high electrical conductivity by the enhanced double exchange process and thereof mitigate the ORR efficiency loss. Further density functional theory calculation reveals that a flat [BO 2 ] plane will make contribution to the charge transfer process from lattice oxygen to adsorbed oxygen (mediated with B ions). Through such exploration of the effect of crystal structure on the electronic state of perovskite oxides, a novel insight into design of highly active ORR catalysts is offered., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Herein, we present heterogeneous hollow multi-shelled structures (HoMSs) prepared by exploiting the properties of the metal-organic framework (MOFs) casing. Through accurately controlling the transformation of MOF layer into different heterogeneous casings, we can precisely design HoMSs of SnO 2 @Fe 2 O 3 (MOF) and SnO 2 @FeO x -C(MOF), which not only retain properties of the original SnO 2 -HoMSs, but also structural information from the MOFs. Tested as anode materials in LIBs, SnO 2 @Fe 2 O 3 (MOF)-HoMSs demonstrate superior lithium-storage capacity and cycling stability to the original SnO 2 -HoMSs, which can be attributed to the topological features from the MOF casing. Making a sharp contrast to the electrodes of SnO 2 @Fe 2 O 3 (particle)-HoMSs fabricated by hydrothermal method, the capacity retention after 100 cycles for the SnO 2 @Fe 2 O 3 (MOF)-HoMSs is about eight times higher than that of the SnO 2 @Fe 2 O 3 (particle)-HoMS., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Ni/CeO 2 enables either methane decomposition or water electrolysis for pure hydrogen production. Ni/CeO 2 , prepared by a sol-gel method with only one heat treatment step, was used to catalyze methane decomposition for the generation of H 2 . The solid byproduct, Ni/CeO 2 /carbon nanotube (CNT), was further employed as an electrocatalyst in the hydrogen evolution reaction (HER) for H 2 production. The Ni/CeO 2 catalyst exhibits excellent activity for methane decomposition because CeO 2 prevents carbon encapsulation of Ni nanoparticles during the preparation process and forms a special metal-support interface with Ni. The derived CNTs act as antenna to improve conductivity and promote the dispersion of agglomerated Ni/CeO 2 . In addition, they provide H 2 diffusion paths and prevent Ni/CeO 2 from peeling off the HER electrode. Although long-term methane decomposition reduces the HER activity of Ni/CeO 2 /CNTs (owing to degradation of the delicate Ni/CeO 2 interface), the tunable nature of the synthesis makes this an attractive sustainable approach to synthesize future high-performance materials., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A Cu metal-organic framework (MOF), [Cu 4 (PMTD) 2 (H 2 O) 3 ]⋅20 H 2 O, 1, (where PMTD is 1,4-phenylenebis(5-methyl-4H-1,2,4-triazole-3,4-diyl)bis(5-carboxylato-3,1-phenylene)bis(hydroperoxymethanide)), with a rare chiral O h -type cage, and dual functionalities of open metal sites and Lewis basic sites, based on a designed U-shaped ligand, was synthesized by hydrothermal methods. It exhibits high CO 2 , C 2 , and C 3 hydrocarbon storage capacity under atmospheric pressure, as well as high H 2 (1.96 wt.%) adsorption capacity at 77 K. Methane purification capacity was tested and verified step by step. Isosteric heats (Q st ) studies reveal that CH 4 has the weakest van der Waals host-guest interactions among the seven gases at 298 K. Ideal adsorbed solution theory (IAST) calculation reveals that compound 1 is more selective toward CO 2 , C 2 H 6 , and C 3 H 8 over CH 4 in further calculating its separation capacity, as exemplified for CO 2 /CH 4 (50:50, 5:95), C 2 H 6 /CH 4 (50:50, 5:95), or C 3 H 8 /CH 4 (50:50, 5:95) binary gas mixtures. Breakthrough experiments show that 1 has a significantly higher adsorption capacity for CO 2 , C 2 H 6 , and C 3 H 8 than CH 4 . The selective adsorption properties of 1 make it a promising candidate for methane purification., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

High Bi-ratio ternary sulfides have been recently reported as superior thermoelectric materials. However, the synthesis of high Bi-ratio Cu-Bi-S nanocrystal remains a challenge. Reported here are the synthesis and characterization of three-phase Cu-Bi-S nanocrystals with the nominal chemical formulae of Cu 1.57 Bi 4.57 S 8 , Cu 2.93 Bi 4.89 S 9 and Cu 3 BiS 3 . The samples were prepared using a Bi 2 S 3 precursor by varying the amount and type of Cu 2-x S (i. e. Cu 2 S or Cu 7.2 S 4 ) reactants. TEM images reveal that two new samples crystalized having nanorod morphology with radii of approximately 50 nm and lengths of 200 nm. XPS results indicate that the valence states of Bi in both the two new phases are +3 with viable oxidation states for Cu. UV-Vis-NIR absorption spectroscopy reveals that narrow direct bandgaps are 1.12 and 1.27 eV for Cu 1.57 Bi 4.57 S 8 and Cu 2.93 Bi 4.89 S 9 , respectively. Besides, this method could also be applied to synthesize the Cu 3 BiS 3 phase with a new nanoplate morphology. The as-synthesized Cu-Bi-S samples show Cu/Bi ratio-dependent photoresponsive properties. This study not only reports the structure and bandgap of two ternary sulfides, which have only been discovered in the mineral previously, but also provides an efficient method for synthesizing Bi-rich ternary chalcogenide nanocrystals., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Black phosphorus (BP) nanosheet (NS) is an emerging oxygen evolution reaction (OER) electrocatalyst with both high conductivity and abundant active sites. However, its ultrathin structure suffers instability because of the lone pair electrons exposed at the surface, which badly restricts durability for achieving long-term OER catalysis. Herein, a facile solvothermal reduction route is designed to fabricate Co/BP NSs hybrid electrocatalyst by in situ growth of cobalt nanoparticles on BP NSs. Notably, electronic structure engineering of Co/BP NSs catalyst is observed by electron migration from BP to Co due to the higher Fermi level of BP than that of Co. Because of the preferential migration of the active lone pairs from the defect of BP NSs, the stability and high hole mobility can be effectively retained. Consequently, Co/BP NSs electrocatalyst exhibits outstanding OER performance, with an overpotential of 310 mV at 10 mA cm -2 , and excellent stability in alkaline media, indicating the potential for the alternatives of commercial IrO 2 . This study provides insightful understanding into engineering electronic structure of BP NSs by fully utilizing defect and provides a new idea to design hybrid electrocatalysts.

In the information age, it is important to protect the security and integrity of the information. As a result, the fluorescent ink as an antifake technology and the fingermark as an information carrier have aroused great interest. In this work, highly water-soluble lanthanide (Ln 3+ )-doped tetragonal phase (t-) LaVO 4 nanoparticles (NPs) are successfully obtained via a simple, fast, and green microwave-assisted hydrothermal method. The average size of t-LaVO 4 NPs is about 43 nm. The aqueous solutions of Ln 3+ -doped t-LaVO 4 exhibit excellent fluorescence properties under ultraviolet light (UV) excitation (t-LaVO 4 :10%Eu is bright red and t-LaVO 4 :0.5%Dy is close to white). Some superb antifake fluorescent patterns are printed using Ln 3+ -doped t-LaVO 4 aqueous solution as ink, which indicates the as-prepared Ln 3+ -doped t-LaVO 4 NPs as fluorescent ink can meet the various antifake requirements. Notably, the designed convenient antifake fluorescent codes with improved security could be directly scanned and decoded by a smart phone. What's more, the as-prepared NPs can be used for the development of latent fingermark on various substrates and the second-level detail information can be clearly obtained from the magnification of a fingermark. These results indicate that the as-prepared Ln 3+ -doped t-LaVO 4 fluorescent NPs have great potential in security application., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The electronic structures of transition metal oxides play a crucial role in the physical and chemical properties of solid materials. Defect engineering is an efficient way to regulate the electronic structure and improve the performance of materials. Here, we develop a defect engineering route that is implemented by controlling the topochemical reactions between cobalt perovskite and urea to optimize the electronic structure of La 0.5 Sr 0.5 CoO 3-δ (LSCO). Urea pyrolysis is able to increase the oxygen defect concentration and cause octahedral distortions. Furthermore, we can distinctly observe that the introduction of oxygen vacancies narrows the hybridization orbital between O 2p and Co 3d and optimizes the O p-band center near the Fermi level by X-ray absorption spectroscopy, which greatly improves the catalytic activity of CO oxidation and photocatalytic water splitting. These results highlight the relationship between oxygen defects, electronic structure, and catalytic activity of perovskite LSCO, and demonstrate a rational approach to defect design and reveal the importance of anion redox chemistry for the structures and properties of perovskite oxides., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Two new isostructural 3D lanthanide-organic frameworks [H 2 N(Me) 2 ] [Ln 3 (OH)(bpt) 3 (H 2 O) 3 ] (DMF) 2 ⋅(H 2 O) 4 (1-Ln; Ln=Sm and Eu) with a 1D channel (25 Å) have been successfully assembled from the rare trinuclear [Ln 3 (OH)(COO) 9 ] clusters and biphenyl-3,4',5-tricarboxylic acid (H 3 bpt) and exhibit high stability towards water in the pH range 3-10. MOF 1-Eu is a promising luminescent probe for sensing Fe 3+ in aqueous solution and is also selective towards rhodamine B (RhB) with a superior adsorption capacity of 735 mg g -1 , which is the highest among the reported Ln-MOFs for RhB removal so far. Periodic DFT calculations further confirmed the selective adsorption of rhodamine B over other dyes., (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Novel wurtzite Cu 3 AlSnS 5 nanocrystals with uniform size and shape are synthesized for the first time using a facile colloidal synthetic approach. The nanocrystals are characterized in detail and have a band gap of 1.35 eV. The photoresponsive behavior indicates their potential application in solar energy conversion devices., (Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Monodisperse water-soluble hexagonal phase Ln(3+)-doped NaGdF(4) upconverting nanocrystals (UCNCs) have been successfully fabricated by means of a fast, facile, and environmentally friendly microwave-assisted route with polyethylenimine as the surfactant. Fine-tuning of the UC emission from visible to near-IR and finally to white light has been achieved. Furthermore, studies of the magnetic resonance imaging as well as the magnetization (magnetization-magnetic field curves) and the targeted recognition properties of FA-coupled amine-functionalized NaGdF(4)@SiO(2) UCNCs indicate that the obtained NaGdF(4) UCNCs can be potential candidates for dual-mode optical/magnetic bioapplications., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)