Tip-Sonicated Red Phosphorus-Graphene Nanoribbon Composite for Full Lithium-Ion Batteries

Phosphorus-Based Materials for High-Performance Alkaline Metal Ion Batteries: Progress and Prospect

Alkaline metal-ion batteries (AIBs) such as lithium-ion batteries (LIBs), sodium-ion batteries (NIBs), and potassium-ion batteries (KIBs) are potential energy storage systems. Currently, although LIBs are widely used in consumer electronics and electric vehicles, the electrochemical performance, safety, and cost of current AIBs are still unable to meet the needs for many future applications, such as large-scale energy storage, due to the low theoretical capacity of cathode/anode materials, flammability of electrolytes and limited Li resources. It is thus imperative to develop new materials to improve the properties of AIBs. Several promising cathodes, anodes, and electrolytes have been developed and among the new battery materials, phosphorus-based (P-based) materials have shown great promise. For example, P and metal phosphide anodes have high theoretical capacity, resource abundance, and environmental friendliness boding well for future high-energy-density AIBs. Besides, phosphate cathode materials have the advantages of low cost, high safety, high voltage, and robust stability, and P-based materials like LiPF₆ and lithium phosphorus oxynitride are widely used electrolytes. In this paper, the latest development of P-based materials in AIBs, challenges, effective solutions, and new directions are discussed.

Two-Dimensional Red Phosphorus Nanosheets: Morphology Tuning and Electrochemical Sensing of Aromatic Amines

Synthesis of 2D materials with different morphologies is of significance to reveal their morphology-dependent properties and further explore their morphology-dependent applications. This work reports the synthesis of 2D red phosphorus nanosheets (RPNSs) with different thicknesses by means of a phosphorus-amine method together with regulated electrophilicity of the solution. With graphene as the support, the RPNSs produced in 0.01 m HCl feature a unique 2D nanostructure, uniform distribution, and excellent electrochemical performance. Originating from the reacted characteristics between phosphorus and amine, the interaction of aniline with the RPNSs is clarified theoretically and experimentally by means of density functional theory, X-ray photoelectron spectroscopy, and voltammetry. A covalent bond is confirmed to be formed during the deprotonation of aniline and its binding energy reaches -2.31 eV. Stemming from such an adsorption process, different aromatic amines (e.g., p-nitroaniline, p-phenylenediamine) are sensitively and selectively monitored on the RPNSs. Consequently, this work provides a new way to clarify morphology-dependent properties and applications of novel 2D materials.

Porous honeycomb-like NiSe2/red phosphorus heteroarchitectures for photocatalytic hydrogen production

Heterojunction construction of semiconductors with a matched bandgap can not only help promote visible light absorption but also restrain photoexcited charge carrier recombination and optimize the separation efficiency. Herein, a novel porous honeycomb-like NiSe₂/RP heterostructure is reported for the first time by in situ deposition of NiSe₂ nanoparticles on the surface of red phosphorus (RP). The optimized binary NiSe₂/RP composite showed superior photocatalytic H₂ evolution activity (1968.8 μmol g^-1 h^-1) from Na₂S/Na₂SO₃ solution under solar light illumination, which was 2.32, 1.90, 1.59 and 1.21 times that of pristine RP, NiSe₂, 5.3% FeS/RP and 8.1% NiS/RP, respectively. The formation process and function of various reactive oxygen species (˙OH, ˙O₂^- and H₂O₂), and the migration pathway of photocarriers are discussed in detail. Such a prominently improved photocatalytic performance could be ascribed to extended light absorption ability, massive reactive centers and lower interfacial transfer resistance, together with expedited charge separation, which arose from a successive two-electron/two-step reduction route. This study provides illuminating insights for the rational exploration and fabrication of potential photocatalytic systems with 0D/3D integrated nanoarchitecture and a multi-step electron transfer process for efficiently realizing solar energy capture and conversion.

Detecting Li Dendrites in a Two-Electrode Battery System

The use of high-energy-density Li metal anodes in rechargeable batteries is not possible because of dendrite formation that can potentially result in a battery fire. Although so-called dendrite-free Li metal anodes have been reported in many recent publications, Li dendrite growth is still kinetically favorable and it remains a severe safety concern in mass production. Here, a detection system capable of alerting for Li dendrite formation in a two-electrode battery with no additional electrodes required is reported. When dendrites contact a red phosphorous-coated separator, dendrite growth is revealed by a significant voltage change. This can activate a signal through the battery management system, warning of the presence of Li dendrites and leading to shutdown of the battery before the dendrites become dangerous.