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Towards the optimization of ceria (CeO2) as a highly efficient, durable, and cost-effective electrocatalyst for CO2 reduction in Solid Oxide Electrolysis Cells (SOECs).

Temperature sensitivity of respiration of forest soils is important for its responses to climate warming and for the accurate assessment of soil carbon budget. The sensitivity of temperature (Ti) to soil respiration rate (Rs), and Q10 defined by e10(lnRs−lna)/Ti has been used extensively for indicating the sensitivity of soil respiration. The soil respiration under a larch (Larix gmelinii) forest in the northern Daxing’an Mountains, Northeast China was observed in situ from April to September, 2019 using the dynamic chamber method. Air temperatures (Tair), soil surface temperatures (T0cm), soil temperatures at depths of 5 and 10 cm (T5cm and T10cm, respectively), and soil-surface water vapor concentrations were monitored at the same time. The results show a significant monthly variability in soil respiration rate in the growing season (April–September). The Q10 at the surface and at depths of 5 and 10 cm was estimated at 5.6, 6.3, and 7.2, respectively. The Q10@10 cm over the period of surface soil thawing (Q10@10 cm, thaw = 36.89) were significantly higher than that of the growing season (Q10@10 cm, growth = 3.82). Furthermore, the Rs in the early stage of near-surface soil thawing and in the middle of the growing season is more sensitive to changes in soil temperatures. Soil temperature is thus the dominant factor for season variations in soil respiration, but rainfall is the main controller for short-term fluctuations in respiration. Thus, the higher sensitivity of soil respiration to temperature (Q10) is found in the middle part of the growing season. The monthly and seasonal Q10 values better reflect the responsiveness of soil respiration to changes in hydrometeorology and ground freeze-thaw processes. This study may help assess the stability of the soil carbon pool and strength of carbon fluxes in the larch forested permafrost regions in the northern Daxing’an Mountains.

Silicon phosphide (SiP) has attracted a great deal of attention in the field of energy storage because of its unique properties of stable semiconducting two-dimensional structure and promising theo...

Developing robust oxygen evolution reaction (OER) electrocatalysts with excellent performance is essential for the conversion of renewable electricity to clean fuel. Herein, we present a facile concept for the synthesis of efficient high-entropy metal-organic frameworks (HEMOFs) as electrocatalysts in a one-step solvothermal synthesis. This strategy allows control of the microstructure and corresponding lattice distortion by tuning the metal ion composition. As a result, the OER activity was improved by optimizing the coordination environment of the metal catalytic center. The optimized Co-rich HEMOFs exhibited a low overpotential of 310 mV at a current density of 10 mA cm

Differences in cooked rice and starch and protein physicochemical properties of three japonica rice were compared systematically. Cultivars of japonica rice, Daohuaxiang2, from Northeast China (NR) and two semiglutinous japonica rice (SGJR), Nangeng46 and Nangeng2728, from the Yangtze River Delta (YRD) were investigated. Both Daohuaxiang2 and Nangeng46 achieved high taste values, but there were great differences in starch and protein physicochemical properties. Daohuaxiang2 showed higher apparent amylose content (AAC), lower protein content (PC), and longer amylopectin (especially fb2 and fb3) and amylose chain lengths, resulting in thicker starch lamellae and larger starch granule size. Its cooked rice absorbed more water and expanded to larger sizes. All of these differences created a more compact gel network and harder but more elastic cooked rice for Daohuaxiang2. Nangeng46 produced a lower AAC, a higher PC, shorter amylopectin and amylose chain lengths, thinner starch lamellae, and smaller starch granule sizes, creating a looser gel network and softer cooked rice. The two SGJR, Nangeng46 and Nangeng2728, had similar low AACs but great differences in taste values. The better-tasting Nangeng46 had a lower PC (especially glutelin content) and higher proportion of amylopectin fa chains, which likely reduced the hardness, improved the appearance, and increased the adhesiveness of its cooked rice. Overall, both types of japonica rice from the NR and YRD could potentially have good eating qualities where Nangeng46’s cooked rice was comparable to that of Daohuaxiang2 because of its lower AC. Moreover, its lower PC and higher proportion of amylopectin fa chains likely improved its eating quality over the inferior-tasting SGJR, Nangeng2728. This research lays a foundation for the improvement of the taste of japonica rice in rice breeding.

Semi-glutinous japonica rice (SGJR) is increasingly a popular choice for rice consumption and more commonly cultivated in the middle and lower reaches of the Yangtze River in China. Here, 58 SGJR and 75 non-semi-glutinous japonica rice (NSGJR) cultivars were evaluated for their characteristics of grain quality by assessing the taste of cooked grains, flour/paste properties, chemical compositions and starch physicochemical properties.Comparisons of factors related to taste showed that cooked rice characteristics of SGJR were better in appearance, lower in hardness, lower in springiness and higher in stickiness. There were no significant differences in contents of total starch and total protein between the two types of rice. Further analysis indicates that thinner lamellar thickness, smaller starch particle size, and higher contents of amylopectin and albumin of SGJR (resulting in higher weights of dried matter from rice slurries) contributed to better appearance of cooked SGJR. Lower contents of amylose and prolamin led to a weaker and less elastic gel network in rice paste samples and contributed to a stronger moisture migration capability of cooked SGJR that showed higher stickiness and lower hardness and springiness.A SGJR line with low apparent amylose content does not indicate good taste. Physicochemical properties of starch and protein contributed to better appearance, higher stickiness and lower hardness and springiness of cooked SGJR. These findings provide empirical data to help breed better-tasting cultivars of japonica rice. © 2021 Society of Chemical Industry.

With the growing demand for high specific volume energy-density, surface modifications are devoted to increasing the electrochemical performances of LiCoO2 at high operating voltage. In this work, LiCoO2 materials with a phosphate-rich coating layer are developed using a facile spray-drying method. The stable phosphate-rich coating layer acts as protection and effectively suppresses the impedance growth in LiCoO2 cells. The phosphate-rich layer coated LiCoO2 samples show long cycle-life and good rate performance when cycled with a high cut-off voltage of 4.5 V at room temperature and 45 °C.

A hexagonal FeSe nanoparticle anode with a novel reaction mechanism and mechanical stability may fully facilitate the desirable rate capability and cycling performance in sodium-ion batteries. In situ TEM reveals that hexagonal FeSe nanoparticle transition to the Fe and Na2Se phase during sodiation, while the products transform to the tetragonal FeSe phase after desodiation.

Layered germanium phosphide (GeP), a recently developed two-dimensional material, promises highly attractive theoretical capacity for use as a lithium-ion battery anode. Here, we comprehensively investigate its electrochemical performance and the modification mechanism. GeP flakes demonstrate large initial discharge/charge capacity and high initial Coulombic efficiency. However, the cycling performance is disappointing in the potential window of 0.001-3 V in which capacity retention is only ∼18% after 100 cycles. In situ transmission electron microscopy reveals that the poor cycling behavior results in the unexpected large volume change induced by complex reaction processes in cycles. Serious cracking and fracture appear clearly on the electrode surface after cycling. Narrowing the working voltage window to 0.001-0.85 V, cycling stability will be greatly enhanced, with 75% capacity retaining after 100 cycles and ∼50% left after 350 cycles due to the absence of the dealloying of Li

Binders play a significant role in the electrochemical performance of electrodes in batteries, especially for high-capacity conversion/alloying-type electrodes. However, the effects of binders on the electrochemical performance of the conversion/alloying-type anodes in sodium ion batteries are not widely investigated. In this work, we use SnS 2 as a model anode and comparatively investigate the performance of six different types of binders in SnS 2 electrodes of sodium ion batteries by half-cell testing. The binders are sodium carboxymethyl cellulose (CMC-Na), sodium polyacrylate (PAA-Na), CMC-Na-PAA-Na (1:1, wt%, denoted as PAA-CMC), sodium alginate (ALG-Na), PVDF, PTFE. The PAA-CMC binder electrodes exhibit outstanding cycling and rate performance, delivering a reversible capacity of 400 mAh g −1 at the current density of 100 mA g −1 within 70 cycles. Our results indicate that the binder with a large fraction of carboxylate and hydroxyl groups, which lead to stronger hydrogen bonds and/or covalent chemical bonds with the carbon black and active materials, is advantageous for the electrochemical performances of SnS 2 electrodes. The synergistic interactions among the binder and the surface of both the active materials of SnS 2 and the conductive additive of ketjen black have been also schematically proposed in this study.

Although various cathode materials have been explored to improve the energy density of lithium-ion batteries, LiCoO2 is still the first choice for 3C consumer electronics due to the high tap density and high volumetric energy density. However, only 0.5 mol of lithium ions can be extracted from LiCoO2 to avoid side reactions and irreversible structure change, which typically occur at high voltage (>4.2 V). To improve the electrochemical performances of the LiCoO2 cathode material at high cut-off voltage and elevated temperature for higher energy density, an in situ formed spinel interfacial coating layer of LiCoxMn2–xO4 is achieved by the reaction of the surface region of the LiCoO2 host. The capacity retention of the modified LiCoO2 cycled at a high voltage of 4.5 V is significantly increased from 15.5 to 82.0% after 300 cycles at room temperature, due to the stable spinel interfacial inhibiting interfacial reactions between LiCoO2 and the electrolyte as confirmed by impedance spectroscopy. We further dem...

The lithium-rich Li[Li0.2Ni0.13Mn0.54Co0.13]O2 nanoplates were synthesized using a molten-salt method. The nanoplates showed an initial reversible discharge capacity of 233 mA&middot, h&middot, g&minus, 1, with a fast capacity decay. The morphology and micro-structural change, after different cycles, were studied by a scanning electron microscope (SEM) and transmission electron microscopy (TEM) to understand the mechanism of the capacity decay. Our results showed that the cracks generated from both the particle surface and the inner, and increased with long-term cycling at 0.1 C rate (C = 250 mA&middot, 1), together with the layered to spinel and rock-salt phase transitions. These results show that the cracks and phase transitions could be responsible for the capacity decay. The results will help us to understand capacity decay mechanisms, and to guide our future work to improve the electrochemical performance of lithium-rich cathode materials.

Although various cathode materials have been explored to improve the energy density of lithium-ion batteries, LiCoO

Layered germanium phosphide, which combines the advantages of both germanium and phosphorus, is believed to be a potential anode for sodium ion battery. Here, the sodium storage mechanism and electrochemical performance of layered germanium phosphide have been deeply investigated by advanced in-situ transmission electron microscopy technique combining half-cell testing. Dynamic reaction process reveals that individual layered germanium phosphide nanoflake undergoes total area expansion of 248% without any detectable fracture or cracking in sodiation. In contrast, germanium phosphide experiences multi-step reactions, i.e. intercalation and alloying, accompanied by sequentially forming NaxGeP (0