Silicon has attracted considerable interest as a high-capacity anode material for next-generation lithium-ion batteries. However, Si-based anodes suffer extreme volume change (≈380%) upon lithiation and delithiation, which results in rapid capacity fading due to mechanical and electrochemical failure during cycling. Herein, a sustainable and scalable method to synthesize hierarchically porous micron-sized Si particles from the low-cost diatomite precursor is reported, which serves as both the precursor and the template. Through a one-step magnesiothermic reduction, the SiO 2 constituent in diatomite is reduced to form a Si/SiO 2 composite network with 10-30 nm crystalline Si domains embedded within an amorphous SiO 2 matrix. Controlling the reduction time leads to an optimal ratio between the crystalline Si and the amorphous SiO 2 constituent, which endows the composite structure with high capacity and excellent cycling stability. For example, 90% capacity can be retained after 500 cycles at 0.2C for sample reduced by 6 h without any coating or prelithiation. The full cell with such Si/SiO 2 as the anode and LiNi 0.8 Co 0.1 Mn 0.1 O 2 as the cathode shows ≈80% capacity retention after 200 cycles. This work creates a unique path towards sustainable and scalable production of high-performance micron-sized Si anodes, offering new opportunities for potential industrial applications.

Microkinetic analysis plays an important role in catalyst design. Although Langmuirian microkinetics is widely used, surface kinetics is actually non-Langmuirian, which depends on the surface nonuniformity caused by either the adsorbate−adsorbate interactions or various types of active sites exposed on the surfaces. Herein we proposed an approach based on the maximum rate analysis for an accurate and efficient analysis of surface kinetics, where the details of the surface nonuniformity were incorporated into the apparent rate coefficients. The present approach was verified by using the water-gas shift reaction on Cu(111) surfaces as a case study. Furthermore, a formulation of free energy landscape (FEL) was proposed to provide a general and intuitive picture of the catalytic reaction network, which was used to understand how surface coverages could affect the values of the macroscopic measurables. Our results demonstrated that even a mild coverage effect, which changed the overall rate only slightly, could significantly change the values of the macroscopic measurables, such as the reaction orders and the apparent activation energies. These were mainly due to the fact that even a mild coverage effect could change the rate-determining steps and weaken the binding strength of some key intermediates. Our results highlight the importance of the coverage-dependent microkinetic analysis aided by the present formulation FEL, which offers a useful tool to bridge theory and experiment and to reveal the in situ nature of the active sites, the rate-determining steps, and the key intermediates, which in turn are beneficial to the rational design of catalysts.

The first examples of linear conjugated organic polymer photocatalysts that produce oxygen from water after loading with cobalt and in the presence of an electron scavenger are reported. The oxygen evolution rates,w hich are higher than for related organic materials,c an be rationalized by acombination of the thermodynamic driving force for water oxidation,t he light absorption of the polymer,a nd the aqueous dispersibility of the relatively hydrophilic polymer particles.W ea lso used transient absorption spectroscopyt o study the best performing system and we found that fast oxidative quenchingofthe exciton occurs (picoseconds) in the presence of an electron scavenger,minimizing recombination.

Cooking has been proven to be a significant source of primary organic aerosol, especially in megacities. However, the formation of secondary organic aerosol (SOA) derived from cooking emissions is still poorly understood. In this work, four prevalent Chinese domestic cooking types involving complicated cuisines and various cooking methods were chosen to conduct a lab simulation for SOA formation using a Gothenburg potential aerosol mass reactor (Go: PAM). After samples had been aged under OH exposures of 4.3−27.1 × 10 10 molecules cm −3 s, the domestic cooking SOA was characterized by mass growth potentialities (1.81−3.16), elemental ratios (O/C = 0.29−0.41), and mass spectra. Compared with other organic aerosol (OA), domestic cooking SOA is a kind of less oxidized oxygenated OA (LO-OOA) with a unique oxidation pathway (alcohol/peroxide pathway) and mass spectra (characteristic peaks at m/z 28, 29, 41, 43, 44, 55, and 57). This study is expected to identify the cooking SOA under actual cooking conditions, which could contribute to the formulation of pollution source control as well as the health risk assessment of exposure to cooking fumes.