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We summarize the direct utilization of versatile waste sources in various electrocatalysis and energy storage systems in view of synthetic strategies, structural properties, electrochemical performance and the challenges and prospects.

Sulfur quantum dots (SQDs), an emerging metal-free quantum dot, which has received intense research interest owing to their unique optical property, good solubility, excellent biocompatibility, and facile synthetic approach. Herein, using sodium hypochlorite as the etching agent, we investigate how it functions and transforms sulfur powder to SQDs and affects the dynamics, photoluminescence, and size changes of SQDs by controlling the reaction time. Precise control of reaction time allows SQDs to be tuned between green and blue (from 515 to 420 nm) with size distribution ranging from 2.0 to 20 nm as well as the occurrence of a distinctive irregular rodlike structure. Surface functional groups and element analysis reveal that the core size and surface oxidizing sulfur species both contribute to the versatile PL properties. Morevoer, we propose a tentative formation mechanism that relies on the oxidizing sulfur surface state and quantum size effect, offering a theoretical and experimental foundation for investigation of we propose a tentative formation mechanism that relies on the oxidizing sulfur surface state and quantum size effect, offering a theoretical and experimental foundation for investigation of the formation and modulation of SQDs.

Rational pore structure and surface properties of carbon materials are significant for their practical application in supercapacitors (SCs). Pursuing a simple and costless synthesis approach is of great importance, yet full of challenges. Herein, heteroatoms-doped hierarchical porous carbon (h-PC) with nanosheets/hollow nanospheres multi-scale structure is fabricated via a facile dual templates strategy with using petroleum asphalt as carbon precursor. The multi-scale pores are controlled by changing the ratio of target templates. Benefitting from high conductivity, plentiful ion-available surfaces, hierarchical porosity with suitable micro-mesoporous channels, and N, O, S heteroatoms, the resultant h-PC electrodes exhibit high specific capacitance of 437 F g−1 at 1 A g−1, and superior rate capability of 336 F g−1 at 50 A g−1 in three-electrode system with KOH electrolyte. The assembled symmetric SCs manifest the maximum energy density of 12.95 Wh kg−1 at 250 W kg−1 and robust cycling stability. Impressively, the energy density is further enhanced to 25.5 Wh kg−1 at 450 W kg−1 with using Na2SO4 electrolyte. Even in all-solid-state symmetric SCs, it still demonstrates an encouraging property. This work may provide new insights for designing advanced carbon-based materials for capacitive energy storage.

We report on recent advancement of CDs derived from various carbon precursors including aromatic small molecules, citric acid, biomass, polymers, petroleum products, and carbon allotropes as well as their optical based applications.

Fe2O3 nanoparticles alleviated Cd uptake mainly via down-regulation of OsNRAMP5, OsCd1, OsIRT1 and OsIRT2 in roots, while the contribution of the enhanced formation of Fe plaque was minor.

Unlike the previous commonly used strong alkaline solvent sodium hydroxide, we employ an eco-friendly solvent, ethanol, as a solvent for the preparation of ultra-small-sized sulfur quantum dots (SQDs). Ethanol can disperse bulk sulfur and allow sufficient transfer of large-sized sulfur to smaller-sized SQDs through a one-pot synthesis approach. The SQDs obtained from ethanol as the solvent displays superior photoluminescence properties to those in water and sodium hydroxide. By delicately controlling the reaction conditions, including the amount of bulk sulfur, the reaction time, and the proportion of sulfur to oxidizing reagent, highly blue emissive SQDs with a photoluminescence quantum yield (PLQY) of 7.04% with ultra-high stability for several months can be successfully prepared. Furthermore, we found out that the SQDs display a dynamic photoluminescence properties and varied particle sizes as the reaction time increases, which is possibly realized

Co-localization of arsenic and silicon at the peripheral tissues and vascular system of rice nodes as revealed by LA-ICP-MS is crucial to understand the key mechanism regulated by foliar application of silica nanoparticles.

New high-voltage cathode materials have been gradually developed, and their discharge voltages can reach more than 5 V ( vs. Li+/Li), but there are very few electrolytes matched with this cathode. Here, we have designed a modified electrolyte containing both FEC and LiDFOB additives which has a high oxidation potential over 5.0V, which perfectly match for high voltage lithium-rich manganese-based cathode. When FEC and LiODFB were added to the basic electrolyte, at 25℃ and 40℃，lithium-rich manganese-based cathode has excellent cycling stability in the voltage range of 2.5-5V. The capacity retention rate of the LMR/Li battery after 200 cycles was 66.5% at 25°C, and 68.7% after 100 cycles at 40°C. The first cycle discharge specific capacity of each system exceeds 200 mAh/g. In contrast, the capacity retention rate of lithium-ion batteries using primary electrolyte is merely 53.6% and 67.6% after cycling at 25 °C and 40 °C. The high-temperature, high-voltage performance exhibited by this formulation is a perfect match for Li-rich manganese-based cathode materials.

TMS used as high-capacity anodes in Li-ion batteries are thoroughly reviewed.

Efficient recycling of high-value metals from spent cathode materials is important in that it not only alleviates the severe shortage of raw material supply but also addresses the environmental and safety issues associated with the disposal of these materials. Here, we report a selective leaching strategy by virtue of the defect-induced lattice instability. In contrast to the traditional “primary leaching – multistep separation” process, this technique enables simultaneous recovery and separation of value metals from the waste cathode by selective dissolution. The feasibility of this technique was first demonstrated by density functional theory (DFT) calculations, and then confirmed by laboratory studies in which a spent LiNi1/3Co1/3Mn1/3O2 material was successfully recycled, where the recoveries of Li, Ni/Co and Mn reached close to 100%, 99.5%/98.2% and 100%, respectively, without the need for a separation step. The recovery of Li, Ni/Co and Mn uses oxalic acid, phosphoric acid and sulfuric acid as leaching agents, respectively. We believe that this work has both practical and theoretical significance, in that the strategy has the potential to be expanded to the recovery/recycling of many other spent materials, and that the atomic-scale insight on the relation between vacancies and lattice stability offers new perspective for developing advanced recycling strategies.

LiNi0.5Mn1.5O4 and LiMn2O4 with novel spinel morphology were synthesized by a hydrothermal and post-calcination process. The synthesized LiMn2O4 particles (5–10 μm) are uniform hexahedron, while the LiNi0.5Mn1.5O4 has spindle-like morphology with the long axis 10–15 μm, short axis 5–8 μm. Both LiMn2O4 and LiNi0.5Mn1.5O4 show high capacity when used as cathode materials for Li-ion batteries. In the voltage range of 2.5–5.5 V at room temperature, the LiNi0.5Mn1.5O4 has a high discharge capacity of 135.04 mA⋅h⋅g−1 at 20 mA⋅g−1, which is close to 147 mA⋅h⋅g−1 (theoretical capacity of LiNi0.5Mn1.5O4). The discharge capacity of LiMn2O4 is 131.08 mA⋅h⋅g−1 at 20 mA⋅g−1. Moreover, the LiNi0.5Mn1.5O4 shows a higher capacity retention (76%) compared to that of LiMn2O4 (61%) after 50 cycles. The morphology and structure of LiMn2O4 and LiNi0.5Mn1.5O4 are well kept even after cycling as demonstrated by SEM and XRD on cycled LiMn2O4 and LiNi0.5Mn1.5O4 electrodes.

Rationally introducing intrinsic defects in porous carbon framework is highly desired for extending the utilizing scope of carbon materials, but it remains a challenge. Herein, a simple yet effective strategy has been proposed to fabricate intrinsic defects-rich porous carbon nanosheets in a sealed tube (S–PCN) by using potassium citrate as the only raw material. The interior pressure in the sealed tube induces the formation of intrinsic defects, and the density of defects can be regulated by the volume of sealed tube. The obtained S-PCNs give rationally organized pore structures with uniformly distributed intrinsic defects. Benefitting from the redistributed surface charges, enhanced wettability, and electrochemical surface area, the supercapacitors with optimal S–PCN as the electrodes perform much higher specific capacitances and excellent rate capability, and deliver a high energy density of 5.54 Wh kg−1 at ultrahigh power density of 50 kW kg−1. In addition, the high density intrinsic defects can also bring strong polarization loss and balance the impedance matching. As a result, even with an ultralow filler loading of 5 wt%, the optimal S–PCN as electromagnetic waves absorbers exhibits a maximum reflection loss as strong as −58.2 dB, meaning that nearly all the incident microwaves can be effectively consumed.

Porous carbon spheres derived from the facile hydrothermal treatment associated with the calcination process exhibit the good spherical morphology and unique porous structure. For the Li-based half-cell test, porous carbon spheres electrode not only exhibits larger reversible capacities and better compatibility as compared to the widely-used graphite, but also provides stable delithiation plateaus under different current density. Additionally, the delithiation ratio below 1 V almost accounts for a constant value (around 70%) with the increase of current density, evidencing that Li intercalation storage is the dominant model and Li insertion/extraction processes are propitious. The lithium ion hybrid capacitor configured with S-doped mesoporous graphene and porous carbon spheres as cathode and anode, delivers satisfied energy and power densities (up to 177 Wh kg−1 and 12,303 W kg−1, respectively) as well as long-term cyclability, which is superior to the corresponding S-doped mesoporous graphene//graphite and activated carbon//porous carbon spheres. In addition, the developed synthesis strategy is in favor of the realization of the scalable production of porous carbon spheres.

Nowadays, rational yet high value-added utilization of low-cost petroleum asphalt still faces a significant challenge. In light of its high carbon content and abundant sulfur atoms, here, an in-situ bonding sulfur strategy is proposed to fabricate transition metal (Mn, Mo, Fe, or Co)-based/carbon composites (TM-based/C). This strategy successfully achieves the conversion from thiophenic-S of asphalt into transition metal sulfides (TMSs). When tested as anodes for lithium-ion batteries (LIBs), the TM-based/C electrodes deliver better specific capacity and cycling performance than those of sulfur-doped carbon nanosheets (SCN) electrode. As a typical example, a 3D network-nanosheets structure of Mn-based/C composite is constructed, and the optimized MnO2/MnS2/C-2 electrode achieves low charging/discharging voltage platform of 1.2 V/0.58 V, and delivers long-term life of 827 mAh g−1 after 400th cycle at 0.5 A g−1. These excellent electrochemical properties benefit from its structural integrity upon cycling and the formation of MnS2/MnO2 phases. Furthermore, LiFePO4/(MnO2/MnS2/C-2) full cell exhibits a remarkably reversible capacity of 168 mAh g−1 at 0.8C, and impressive cycling stability of 78% after 400 cycles at 1 C, better than those of LiFePO4/(commercial graphite). This work may provide a new perspective for the high value-added utilization of low-cost petroleum asphalt for efficient anodes toward LIBs.

The consumption of rechargeable batteries has been increasing rapidly. High demand on specific metals for battery manufacturing and environmental impacts from battery disposal make it essential to recycle and retrieve materials from the spent batteries. There have been some review articles on battery recycling, mostly on the technologies for the materials recovery and some on life cycle assessment (LCA). To develop a truly sustainable battery industry, however, battery recycling must be commercially viable. Yet, very limited information on the economics of battery recycling is available. This paper examines technologies and research efforts in battery recycling from the perspective of economic viability and life cycle inventory. With the support of up-to-date statistics, the paper also comments on the challenges facing battery recycling, and the role of battery design and circular economy in the sustainable development of battery industry where governments, manufacturers and consumers all play a part.

Isodimorphism and isomorphism are becoming mature approaches but separately used to regulate crystallization behavior of random copolymers and thus their performances. Most of the research work is ...

Design and synthesis of advanced electrode materials with fast and stable ion storage are of importance for energy storage applications. Herein, we propose that introducing the heterogeneous interf...

Cell wall polysaccharides play a vital role in binding with toxic metals such as copper (Cu) ions. However, it is still unclear whether the major binding site of Cu in the cell wall varies with different degrees of Cu stresses. Moreover, the contribution of each cell wall polysaccharide fraction to Cu sequestration with different degrees of Cu stresses also remains to be verified. The distribution of Cu in cell wall polysaccharide fractions of castor (Ricinus communis L.) root was investigated with various Cu concentrations in the hydroponic experiment. The results showed that the hemicellulose1 (HC1) fraction fixed 44.9%–67.8% of the total cell wall Cu under Cu stress. In addition, the pectin fraction and hemicelluloses2 (HC2) fraction also contributed to the Cu binding in root cell wall, accounting for 11.0%–25.9% and 14.1%–26.6% of the total cell wall Cu under Cu treatments, respectively. When the Cu levels were ≤ 25 μmol/L, pectin and HC2 contributed equally to Cu storage in root cell wall. However, when the Cu level was higher than 25 μmol/L, the ability of the pectin to bind Cu was easy to reach saturation. Much more Cu ions were bound on HC1 and HC2 fractions, and the HC2 played a much more important role in Cu binding than pectin. Combining fourier transform infrared (FT-IR) and two-dimensional correlation analysis (2D-COS) techniques, the hemicellulose components were showed not only to accumulate most of Cu in cell wall, but also respond fastest to Cu stress.