Revealing the delithiation process of spent LiMn2O4 and LiNi0.6Co0.2Mn0.2O2 batteries during the biomass-assisted gasthermal and carbothermal reduction.

The utilization of biomass-assisted pyrolysis in the recycling of spent lithium-ion batteries has emerged as a promising and reliable process. This article furnishes theoretical underpinnings and analytical insights into this method, showcasing sawdust pyrolysis reduction as an efficient means to recycle spent LiMn2O4 and LiNi0.6Co0.2Mn0.2O2 batteries. Through advanced thermogravimetry-gas chromatography-mass spectrometry analysis complemented by traditional thermodynamic demonstration, the synergistic effects of biomass pyrolysis reduction are elucidated, with minor autodecomposition and major carbothermal and gasthermal reduction pathways identified. The controlled manipulation of transition metals has demonstrated the capability to modulate surface pyrolysis gas catalytic reactions and facilitate the preparation of composite materials with diverse morphologies. Optimization of process conditions has culminated in recovery efficiency exceeding 99.0 % for LiMn2O4 and 99.5 % for LiNi0.6Co0.2Mn0.2O2. Economic and environmental analyses underscore the advantages of biomass reduction and recycling for these two types of spent LIBs: low energy consumption, environmental compatibility, and high economic viability.

Determining the mechanism of the root effect on soil detachment under mixed modes of different plant species using flume simulation.

Soil detachment is the separation and dislodgment of soil particles from a soil mass by the force of raindrops and flow, which is also the initial process of soil erosion. Plant roots have significant effects on the soil detachment rate (SDR). Current studies have mainly focused on root effects on the SDR under single species. Because it is difficult to identify the roots of different species in mixed-plant areas, few studies have evaluated the root effects on the SDR under mixed-plants. Natural, undisturbed soil samples containing roots were collected from four natural sampling plots with single plant types, and six natural sampling plots with mixed plant types. Bare soil was used as the control. The samples were subjected to flow scouring through indoor hydraulic flume experiments under six shear stresses (3.65, 7.28, 7.67, 8.59, 10.15, and 12.19 Pa). The results showed that the root reduction effect on the SDR under the mode of tap roots mixed with fibrous roots was 55.54 % weaker than that the mode of fibrous roots mixed with other fibrous roots. When fibrous roots were mixed with tap roots, the fibrous roots indirectly affected the SDR through soil mechanical properties, while the indirect path of the tap roots on the SDR was not unique. However, the indirect effect of roots on the SDR was weaker than the direct effect. The mixed roots affected the SDR mainly by rill erodibility, not critical shear stress. The variation in rill erodibility at the mixed root sites was similar to the SDR variation at those sites. The mode of grasses with fibrous roots mixed with other grasses with fibrous roots was considered as better for soil and water vegetation conservation.

Preparation of Gold Nanoplates Using Ortho Carbonyl Compounds as Capping Agents for Electrochemical Sensing of Lead Ions.

In this study, gold nanoplates were synthesized using plant molecules (gallic acid) following a kinetic control mode. The growth of nanoplates is mainly due to the specific adsorption of capping agents on certain crystal facets. Through systematical characterizations, it is found that the distance between two oxygen atoms in ortho carbonyl compounds matches well with the lattice spacing of gold (111) facets exactly, which is beneficial to the formation of twin seeds and further the growth of plate-like gold nanoparticles. The gold nanoplates on glassy carbon electrode show a remarkably improved electrochemical sensing activity of lead ions compared to the bare glassy carbon electrode or spherical gold nanoparticle-modified electrode. The modified electrode is expected to be used in the detection of lead ion concentration in heavy metal wastewater.