Abstract
Electrode materials are key components in typical batteries, where the electrodes are generally fabricated onto current collectors in solid forms and are isolated by a separator. However, ...the preparation of the electrodes increases the fabrication complexity, which speeds down their large‐scale production. Here, series of static electrode‐less MnO
2
‐metal batteries are presented that are facilely fabricated by using carbon current collectors and electrolytes. The MnO
2
‐metal batteries are operated in dual‐deposition/stripping chemistries of Mn
2+
/MnO
2
on the cathode and M/M
x+
on the anode. The MnO
2
‐Cd/Zn/Cu batteries exhibit remarkable rates up to 200 C, excellent reversibility of 15 000 cycles, and realistic gravimetric and volumetric energy densities of 93.7 Wh kg
−1
and 134 Wh L
−1
, respectively. Impressively, the MnO
2
‐Cd battery can achieve over 160 000 cycles in the high current pulse test, showing promises in the applications of electrical vehicle's start‐stop and large‐scale energy storage.
Light-driven valorization conversion of CO2 is an encouraging carbon-negative pathway that shifts energy-reliance from fossil fuels to renewables. Herein, a hierarchical urchin-like ...hollow-TiO2@CdS/ZnS (HTO@CdS/ZnS) Z-scheme hybrid synthesized by an in situ self-assembly strategy presents superior photocatalytic CO2-to-CO activity with nearly 100% selectivity. Specifically, benefitting from the reasonable architectural and interface design, as well as surface modification, this benchmarked visible-light-driven photocatalyst achieves a CO output of 62.2 μmol·h–1 and a record apparent quantum yield of 6.54% with the Co(bpy)3 2+ (bpy = 2,2′-bipyridine) cocatalyst. It rivals all the incumbent selective photocatalytic conversion of CO2 to CO in the CH3CN/H2O/TEOA reaction systems. Specifically, the addition of HTO and stabilized ZnS enables the photocatalyst to effectively upgrade optical and electrical performances, contributing to efficient light-harvesting and photogenerated carrier separation, as well as interfacial charge transfer. The tremendous enhancement of photocatalytic performance reveals the superiority of the Z-scheme heterojunction assembled from HTO and CdS/ZnS, featuring the inner electric field derived from the band bending of HTO@CdS/ZnS make CdS resistant to photocorrosion. This study allows access to inspire studies on rationally modeling and constructing diverse heterostructures for the storage and conversion of renewables and chemicals.
Efficient photocatalytic reduction of CO2 to high‐calorific‐value CH4, an ideal target product, is a blueprint for C1 industry relevance and carbon neutrality, but it also faces great challenges. ...Herein, we demonstrate unprecedented hybrid SiC photocatalysts modified by Fe‐based cocatalyst, which are prepared via a facile impregnation‐reduction method, featuring an optimized local electronic structure. It exhibits a superior photocatalytic carbon‐based products yield of 30.0 µmol g−1 h−1 and achieves a record CH4 selectivity of up to 94.3%, which highlights the effectiveness of electron‐rich Fe cocatalyst for boosting photocatalytic performance and selectivity. Specifically, the synergistic effects of directional migration of photogenerated electrons and strong π‐back bonding on low‐valence Fe effectively strengthen the adsorption and activation of reactants and intermediates in the CO2 → CH4 pathway. This study inspires an effective strategy for enhancing the multielectron reduction capacity of semiconductor photocatalysts with low‐cost Fe instead of noble metals as cocatalysts.
Electron‐rich Fe in cocatalyst can provide strong π‐back bonding between the active site and CO2 molecules, facilitating the adsorption and activation of CO2 in the artificial synthesis of CH4. Additionally, the intramolecular contact between Fe species and SiC enhances the transport efficiency of photogenerated carrirs. Profited from these synergies, a satisfactory photocatalytic CH4 evolution with ultrahigh selectivity of 94.3% has been achieved.
Let be a simple Lie algebra of rank l over an algebraically closed field of characteristic zero, an arbitrary parabolic subalgebra of . A bilinear map ϕ: × → is called a biderivation of if it is a ...derivation with respect to both components, meaning that
for all x, y, z ∈ . It is shown in this article that a bilinear map ϕ: × → is a biderivation if and only if it is a sum of an inner and an extremal biderivation.
Heat conduction in real physical networks such as nanotube/nanowire networks has been attracting more and more attention, but its theoretical understanding is far behind. To open a way to this ...problem, we present a multi-body vibration model to study heat conduction in complex networks, where nodes’ degrees satisfy a random distribution, and links consist of 1D atom chains with nonlinear springs. Based on this model, we find two interesting phenomenons: (1) The main heat fluxes of a network always localize in a skeleton subnetwork, which may have potential applications in thermal management and thermal concentrators, and (2) there exists an abnormal size effect of heat conduction in complex networks, i.e., the total heat flux of a network will enlarge with the increase of atoms on links, which is in contrast to the previous result on a 1D chain. Furthermore, we introduce a transmission diagram to characterize the skeleton of localized heat fluxes and then discover a jumping transition of total heat flux in the process of removing links, implying that the control of heat flux can be effective only when the change in a network topology focuses on the links within the skeleton. A brief theory is introduced to explain the abnormal size effect.
Efficient artificial photosynthesis of disulfide bonds holds promises to facilitate reverse decoding of genetic codes and deciphering the secrets of protein multilevel folding, as well as the ...development of life science and advanced functional materials. However, the incumbent synthesis strategies encounter separation challenges arising from leaving groups in the ─S─S─ coupling reaction. In this study, according to the reaction mechanism of free‐radical‐triggered ─S─S─ coupling, light‐driven heterojunction functional photocatalysts are tailored and constructed, enabling them to efficiently generate free radicals and trigger the coupling reaction. Specifically, perovskites and covalent organic frameworks (COFs) are screened out as target materials due to their superior light‐harvesting and photoelectronic properties, as well as flexible and tunable band structure. The in situ assembled Z‐scheme heterojunction MAPB‐M‐COF (MAPbBr3 = MAPB, MA+ = CH3NH2+) demonstrates a perfect trade‐off between quantum efficiency and redox chemical potential via band engineering management. The MAPB‐M‐COF achieves a 100% ─S─S─ coupling yield with a record photoquantum efficiency of 11.50% and outstanding cycling stability, rivaling all the incumbent similar reaction systems. It highlights the effectiveness and superiority of application‐oriented band engineering management in designing efficient multifunctional photocatalysts. This study demonstrates a concept‐to‐proof research methodology for the development of various integrated heterojunction semiconductors for light‐driven chemical reaction and energy conversion.
Precise band engineering management and modulation of nanoheterojunctions assembled by superior semiconductor photoabsorber hold promise for efficient solar conversion. The Z‐scheme heterojunction enables a trade‐off between photo quantum efficiency and chemical redox potentials. The solar‐driven synthesis of disulfide bonds without inseparable leaving groups over Z‐scheme nanoheterojunction photocatalyst is an attractive route for the development of semiconductor materials.
The direct 3,3′-dimerization of BODIPYs lacking substituent groups in the 1,2,6, and 7 positions was developed by oxidative coupling with FeCl 3 . This regioselective dimerization was achieved for ...BODIPYs substituted only in the 5-position with Cl or aryl groups. Further functionalization of the 5,5′-dichloride dimer gave the corresponding pyrrole or 4-(2-aminoethyl)morpholine disubstituted dimers 2f and 2g, respectively. While dimer 2f exhibited intense NIR absorption/emission maxima at 773/827 nm in toluene, dimer 2g showed favorable lysosome-targeting NIR fluorescence in living cells.
Dynamic and heterogeneous interaction between tumor cells and the surrounding microenvironment fuels the occurrence, progression, invasion, and metastasis of solid tumors. In this process, the tumor ...microenvironment (TME) fractures cellular and matrix architecture normality through biochemical and mechanical means, abetting tumorigenesis and treatment resistance. Tumor cells sense and respond to the strength, direction, and duration of mechanical cues in the TME by various mechanotransduction pathways. However, far less understood is the comprehensive perspective of the functions and mechanisms of mechanotransduction. Due to the great therapeutic difficulties brought by the mechanical changes in the TME, emerging studies have focused on targeting the adverse mechanical factors in the TME to attenuate disease rather than conventionally targeting tumor cells themselves, which has been proven to be a potential therapeutic approach. In this review, we discussed the origins and roles of mechanical factors in the TME, cell sensing, mechano‐biological coupling and signal transduction, in vitro construction of the tumor mechanical microenvironment, applications and clinical significance in the TME.
Polydispersed CoP nanoparticles in an orthorhombic phase were synthesized via a gas–solid reaction and then deposited over graphitic carbon nitride to build the CoP/g-C3N4 (CoP–CN) heterostructure. ...Nanorod-like CoP nanoparticles with a length of 10–80 nm were connected to g-C3N4 nanosheets to build an intimate face-to-face contact via their crystal planes of (011) and (211). This unique heterojunction hybrid exhibits superior photocatalytic and photoelectrochemical performances for H2 evolution and photoelectrochemical response plus excellent overall water-splitting activity. The optimal sample of 3% CoP–CN composite achieved a superior hydrogen production rate at 1038.1 μmol h–1 g–1 when irradiated by simulated solar light, exhibiting a much higher photocurrent at 150 μA cm–2 compared to pure g-C3N4. Also, a larger anodic current density was detected during the photoelectrochemical hydrogen evolution reactions (PEC HERs) with enhanced applied bias photon-to-current efficiency, denoting a higher efficiency for PEC HER. The enhancements for photocatalytic and PEC HER activity are mainly attributed to the formation of intimate interfacial contact for better light absorption, stronger photoreductive potentials, and higher efficiency for charge separation and transfer. This study provides a proof-of-concept design and construction of effective cobalt-phosphide-based heterojunctions for hydrogen evolution and water-splitting applications.
Photocatalytic selective oxidation of CH4 to value-added higher hydrocarbons constructs a promising avenue for sustainable development of the chemical industry; however, the mild activation and ...conversion of CH4 is still a great challenge. Herein, a novel Au/Zn2Ti3O8 hybrid photocatalyst is assembled by supporting Au nanoparticles on the surface of Zn2Ti3O8 nanospheres. When irradiated by a 365 LED light, the Au/Zn2Ti3O8 catalyst manifests high activity and stability for selective coupling of CH4 with O2, affording an optimal C2H6 yield of 610 umol g-1 h-1 with 80 % selectivity, which is among the state-of-the-art values under comparable conditions. Studies reveal that the Schottky junction interface strongly promotes photoinduced electrons to be transferred to Au from Zn2Ti3O8, realizing directed separation and migration of the charge carriers for high photocatalytic activity. Various in-situ spectroscopy analyses expose that the key •CH3 species in CH4-to-C2H6 conversion are stabilized by the surface Au sites, which quells the undesirable overoxidation reaction to enhance C2H6 selectivity. The possible photocatalytic oxidation CH4 coupling mechanism over the Au/Zn2Ti3O8 hybrid is also proposed.
