A sheet-like tin-based metal-organic framework with enhanced lithium storage.

A novel sheet-like tin-based metal-organic framework exhibited a specific capacity for lithium storage as high as 1033.3 mAh g-1 at 200 mA g-1 with excellent cycling stability. This framework, due to its unique porous structure and multiple lithium storage sites, could better cope with challenges occurring during lithium insertion/extraction than could traditional tin materials.

Fundamentals and Recent Progress in Magnetic Field Assisted CO2 Capture and Conversion.

CO2 capture and conversion technology are highly promising technologies that definitely play a part in the journey towards carbon neutrality. Releasing CO2 by mild stimulation and the development of high efficiency catalytic processes are urgently needed. The magnetic field, as a thermodynamic parameter independent of temperature and pressure, is vital in the enhancement of CO2 capture and conversion process. In this review, the recent progress of magnetic field-enhanced CO2 capture and conversion is comprehensively summarized. The theoretical fundamentals of magnetic field on CO2 adsorption, release and catalytic reduction process are discussed, including the magnetothermal, magnetohydrodynamic, spin selection, Lorentz forces, magnetoresistance and spin relaxation effects. Additionally, a thorough review of the current progress of the enhancement strategies of magnetic field coupled with a variety of fields (including thermal, electricity, and light) is summarized in the aspect of CO2 related process. Finally, the challenges and prospects associated with the utilization of magnetic field-assisted techniques in the construction of CO2 capture and conversion systems are proposed. This review offers a reference value for the future design of catalysts, mechanistic investigations, and practical implementation for magnetic field enhanced CO2 capture and conversion.

Photothermal CO-PROX reaction over ternary CuCoMnOx spinel oxide catalysts: the effect of the copper dopant and thermal treatment.

The purification of carbon monoxide in H2-rich streams is an urgent problem for the practical application of fuel cells, and requires the development of efficient and economical catalysts for the preferential oxidation of CO (CO-PROX). In the present work, a facile solid phase synthesis method followed by an impregnation method were adopted to prepare a ternary CuCoMnOx spinel oxide, which shows superior catalytic performance with CO conversion of 90% for photothermal CO-PROX at 250 mW cm-2. The dopant of copper species leads to the incorporation of Cu ions into the CoMnOx spinel lattice forming a ternary CuCoMnOx spinel oxide. The appropriate calcination temperature (300 °C) contributes to the generation of abundant oxygen vacancies and strong synergetic Cu-Co-Mn interactions, which are conducive to the mobility of oxygen species to participate in CO oxidation reactions. On the other hand, the highest photocurrent response of CuCoMnOx-300 also promotes the photo-oxidation activity of CO due to the high carrier concentration and efficient carrier separation. In addition, the in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) confirmed that doping copper species could enhance the CO adsorption capacity of the catalyst due to the generation of Cu+ species, which significantly increased the CO oxidation activity of the CuCoMnOx spinel oxide. The present work provides a promising and eco-friendly solution to remove the trace CO in H2-rich gas over CuCoMnOx ternary spinel oxide with solar light as the only energy source.

Intermediate-Controlled Interfacial Engineering for Stable and Highly Efficient Carbon-Based PSCs.

A major bottleneck hindering the performance and commercial application of cost-effective carbon-based perovskite solar cells (C-PSCs) is the contact issue at the interface of the perovskite layer and the carbon counter electrode. Herein, a new approach of intermediate-controlled interfacial engineering (IIE) utilizing an ultra-low-cost acetylene black material is developed for the first time that can improve the interfacial contact of C-PSCs. We achieved both high efficiency (16.41%) without hole-transport materials and good stability as a result of the optimal heterogeneous interfacial contact. Devices without any encapsulation consistently exhibit excellent environmental stability, retaining 93% of their original efficiency by storing in an ambient atmosphere (30 °C, 30% RH) for 2000 h and achieving 81% of their original efficiency by storing in a terrible air environment (85 °C, 65% RH) for 312 h. In addition, to acquire a deep understanding of carrier transport, a comparison of heterogeneous interfaces fabricated using different methods has been undertaken. In C-PSCs fabricated by the IIE method, the lower radioactive recombination and faster carrier transfer result in a shorter carrier lifetime. We present a promising future for the industrialization of C-PSCs by reducing the costs and improving the performance.

Excellent Moisture Stability and Efficiency of Inverted All-Inorganic CsPbIBr2 Perovskite Solar Cells through Molecule Interface Engineering.

All-inorganic lead halide perovskite solar cells (PSCs) have drawn widespread interest because of its excellent thermal stability compared to its organic-inorganic hybrid counterpart. Poor phase stability caused by moisture, however, has thus far limited their commercial application. Herein, by modifying the interface between the hole-transport layer (HTL) and the perovskite light absorption layer, and by optimizing the HTL for better energy alignment, we controlled the growth of perovskite, reduced carrier recombination, facilitated carrier injection and transport, and improved the PSC's power conversion efficiency (PCE) and moisture stability. When testing using a positive bias scan, we obtained a significant improvement in PCE, 9.49%, which is the champion efficiency of CsPbIBr2-based inverted PSC at present. The stability measurement shows that the passivated CsPbIBr2-based inverted PSCs can retain 86% of its initial efficiency after 1000 h preserved in ambient air with 65% relative humidity. This study paves a new way for enhancing the moisture stability and power conversion efficiency of CsPbIBr2-based PSCs.

A black phosphorus/Ti3C2 MXene nanocomposite for sodium-ion batteries: a combined experimental and theoretical study.

A black phosphorus (BP)/Ti3C2 MXene composite was prepared by compositing small BP nanoparticles with exfoliated Ti3C2 layers. When used as an anode for sodium-ion batteries, the BP/Ti3C2 composite electrode exhibited higher specific capacity and better electrode stability than a BP electrode and a Ti3C2 electrode. The results of experimental and density functional theory (DFT) calculations illustrated that the synergy of BP and Ti3C2 based on a stable interfacial interaction simultaneously reduces the resistances from both electron and Na+ transport, resulting in the impressive electrochemical performance of the BP/Ti3C2 composite in sodium-ion batteries. The synthesis process and research concept could also be extended for further application of MXene materials and studies on sodium-ion batteries.

N-Doped 3D Interconnected Carbon Bubbles as Anode Materials for Lithium-Ion and Sodium-Ion Storage with Excellent Performance.

In this paper, we develop a novel N-doped 3D interconnected carbon bubbles (NCBs) by a facile method of nitric acid extraction precursor at room temperature for the lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The NCBs with hollow carbon bubbles having a size of ~100 nm interconnected to each other exhibits high specific surface area and abundant active sites, which ensures continuous diffusion paths for ions and electrons and keeps the electrode structure more stable, thus significantly enhancing the lithium-ion and sodium-ion storage capability. In lithium-ion batteries, the NCBs electrode shows a high reversible capacity of 1180 mA h g-1 after 380 cycles at a current density of 1 C. As the current density increased from 1 to 10 C, the capacity still retains 407.1 mA h g-1. While in sodium-ion batteries, the NCBs electrode provides a capacity of 222.5 mA h g-1 after 200 cycles at a current density of 50 mA g-1. And the capacity maintains at 107.5 mA h g-1 even the current density increased from 0.05 to 5 A g-1. The excellent cycling performance and high-rate capability should be attributed to the synergistic effect of the 3D interconnected hollow structure and the incorporation of nitrogen atoms.

Hierarchical NiCo2 S4 Nanotube@NiCo2 S4 Nanosheet Arrays on Ni Foam for High-Performance Supercapacitors.

Hierarchical NiCo2 S4 nanotube@NiCo2 S4 nanosheet arrays on Ni foam have been successfully synthesized. Owing to the unique hierarchical structure, enhanced capacitive performance can be attained. A specific capacitance up to 4.38 F cm(-2) is attained at 5 mA cm(-2) , which is much higher than the specific capacitance values of NiCo2 O4 nanosheet arrays, NiCo2 S4 nanosheet arrays and NiCo2 S4 nanotube arrays on Ni foam. The hierarchical NiCo2 S4 nanostructure shows superior cycling stability; after 5000 cycles, the specific capacitance still maintains 3.5 F cm(-2) . In addition, through the morphology and crystal structure measurement after cycling stability test, it is found that the NiCo2 S4 electroactive materials are gradually corroded; however, the NiCo2 S4 phase can still be well-maintained. Our results show that hierarchical NiCo2 S4 nanostructures are suitable electroactive materials for high performance supercapacitors.

Hydrogen generation from Al-NiCl2/NaBH4 mixture affected by lanthanum metal.

The effect of La on Al/NaBH(4) hydrolysis was elaborated in the present paper. Hydrogen generation amount increases but hydrogen generation rate decreases with La content increasing. There is an optimized composition that Al-15 wt% La-5 wt% NiCl(2)/NaBH(4) mixture (Al-15 wt% La-5 wt% NiCl(2)/NaBH(4) weight ratio, 1 : 3) has 126 mL g(-1 )min(-1) maximum hydrogen generation rate and 1764 mL g(-1) hydrogen generation amount within 60 min. The efficiency is 88%. Combined with NiCl(2), La has great effect on NaBH(4) hydrolysis but has little effect on Al hydrolysis. Increasing La content is helpful to decrease the particle size of Al-La-NiCl(2) in the milling process, which induces that the hydrolysis byproduct Ni(2)B is highly distributed into Al(OH)(3) and the catalytic reactivity of Ni(2)B/Al(OH)(3) is increased therefore. But hydrolysis byproduct La(OH)(3) deposits on Al surface and leads to some side effect. The Al-La-NiCl(2)/NaBH(4) mixture has good stability in low temperature and its hydrolytic performance can be improved with increasing global temperature. Therefore, the mixture has good safety and can be applied as on board hydrogen generation material.