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Mn-rich olivine phosphates (LiMn x Fe 1−x PO 4 , x>0.6) are promising cathode candidates for Li-ion batteries (LIBs) with high energy density and low cost. However, it suffers voltage decay which causes severe energy loss and is considered as a crucial barrier on the way to application. Here, using LiMn 0.7 Fe 0.3 PO 4 as a model, we reveal that the increasing non-synchronous reaction among particles is an important cause for the voltage decay. Specifically, during lithiation, the inhomogeneity between particles is autoaccelerating and accumulating with cycling. While the inhomogeneity between particles may be overwhelmed by fast kinetics during delithiation, causing little change in the charge curves. The deteriorated kinetic of Li+ diffusion in the Mn2+↔Mn3+ plateau postpones the response of Mn 0.7 Fe 0.3 PO 4 (MFP) phase and causes a different evolution of heterogeneity during lithium-ion insertion/extraction. In addition, by applying an electrode additive to enhance electron transfer to each LiMn 0.7 Fe 0.3 PO 4 particle, the voltage decay and energy decay of the LiMn 0.7 Fe 0.3 PO 4 electrode can be greatly suppressed. This study pinpoints a new insight into the degradation of LiMn 0.7 Fe 0.3 PO 4 electrode, and discloses effective designs of electrode architecture to achieve long-life batteries. [Display omitted] • Using LiMn 0.7 Fe 0.3 PO 4 as a model, the increasing non-synchronous reaction among particles causes the voltage decay. • Inhomogeneity between particles is autoaccelerating during lithiation, accumulating with cycling. • The voltage decay is greatly diminished for the LiMn 0.7 Fe 0.3 PO 4 with electrode additive. [ABSTRACT FROM AUTHOR]

The effective utilization of biomass resources can bring significantly environmental and economic benefits. In this context, tea saponin, which can be easily and extensively extracted from the oil cake as the biomass waste during the seed oil production from camellia seeds, is explored as the precursor to synthesize porous carbon bearing abundant –OH and –COOH groups via a simple carbonization process. Owing to the obtained porous structure and existence of rich oxygen-containing groups serving as Lewis acidic sites, the carbonized tea saponin (CTS) can display impressive catalytic activities for CO 2 cycloaddition reaction with both high selectivity (> 99%) and high yield of target cyclic carbonate under either thermally driven (80 °C and 0.1 MPa CO 2) or photo-thermally driven (UV-Vis light irradiation with the light intensity of 350 mW/cm2) conditions. In addition, benefiting from the good chemical stability, CTS can be reused for many cycles with almost no catalytic activity loss, making CTS a promising biomass-based catalyst for CO 2 fixation under mild conditions. [Display omitted] • Tea saponin-derived carbon (CTS) with rich –OH and –COOH groups was obtained. • CTS displays impressive catalytic activities for CO 2 cycloaddition. • CTS can drive CO 2 cycloaddition reaction thermally and photothermally. [ABSTRACT FROM AUTHOR]

• Zeolitic imidazolate frameworks (ZIFs) with different dimensions were synthesized. • The electrochemical performance of ZIFs is dimensional-dependent. • One-dimensional ZIF performs best owing to the morphological and textural merits. So far, direct utilization of zeolitic imidazolate frameworks (ZIFs) as the electrode materials for high-performance supercapacitors (SCs) is challenging owing to their poor electrochemical performance. However, for the first time, the electrochemical activities of ZIFs are found to be dimensional dependent in this study, and can be greatly boosted by reducing the dimension from three-dimension (3D) or two-dimension (2D) to one-dimension (1D). The unique 1D architecture endows 1D ZIF with improved conductivity as well as a high surface-to-volume ratio to facilitate the accessibility of electrolyte ions. Additionally, 1D ZIF is highly defective with abundant linker-missing defects, leading to the favorable exposure of cobalt ions as the redox active sites responsible for pseudocapacitance. Benefiting from these structural and textural merits, 1D ZIF exhibits a much higher charge storage capacity, rate capability and cycling stability than 2D and 3D ZIF. When assembled with activated carbon (AC), the asymmetric supercapacitor device (1D ZIF//AC) can deliver an impressive energy density of 76 Wh kg−1 at a power density of 800 W kg−1, superior to many other ZIFs, ZIF-based composites, ZIF-derived carbon, and even some advanced metal compounds reported in literature. [Display omitted] [ABSTRACT FROM AUTHOR]

Interest in production and utilization of 5-hydroxymethylfurfural (5-HMF) has risen greatly as 5-HMF is considered as an extremely important platform compound. It remains a huge challenge to develop efficient and low-cost solid catalysts with suitable acid properties for sustainable production of 5-HMF from glucose. Herein, a bifunctional Sn-modified SBA-15 (Sn–OH/SBA-15) catalyst containing both Lewis and Brønsted acid sites was fabricated. Dimethyldichlorostannane was grafted onto mesoporous SBA-15, and the methyl groups were then converted to hydroxyl groups by calcination. The synergistic effects of Lewis and Brønsted acid significantly boosted the synthesis of 5-HMF from glucose adopting the one-pot method. By optimizing the reaction conditions, the Sn–OH/SBA-15 sample was able to achieve a glucose conversion of 96.9% with a 5-HMF yield of 70.6% (180 °C, 5 h). Moreover, the catalyst demonstrated superior recyclability and reusability. This work would enlighten the exploitation and preparation of highly efficient catalysts for the transformation of carbohydrates into value-added chemicals. [Display omitted] • Solid catalyst is used for transformation of glucose to 5-HMF. • Mesoporous structure and appropriate acid sites favor the production of 5-HMF. • A high 5-HMF yield of 70.6% is achieved by adding Sn–OH/SBA-15. [ABSTRACT FROM AUTHOR]

Interfacial evaporation through hydrogel-based evaporators is emerging as a sustainable and cost-effective strategy for drinkable water production. Herein, a specially designed bi-layer hydrogel evaporator was fabricated and used for efficient solar water desalination. With cotton linter as cellulose precursor, it was dispersed in a highly concentrated ZnCl 2 (65 %) solution, and cross-linked by epichlorohydrin to prepare cellulose composite hydrogel. After removing inorganic salts by salt-leaching, polyaniline (PANi) with broadband and wide-range light absorption was then integrated into the top surface of hydrogel through in situ polymerization to construct a bi-layer evaporator. As a solar evaporator, the water could be evaporated with a low-energy demand, and the heat from the sunlight could be confined at the interface to achieve efficient water evaporation. Therefore, the hydrogel evaporator demonstrates an optimal water evaporation rate of 3.02 kg m−2 h−1 and photothermal conversion efficiency of 89.09 % under 1 sun (1 kW m−2) irradiation. This work provides new possibilities for efficient solar water purification systems with assured water quality. [Display omitted] [ABSTRACT FROM AUTHOR]