We developed a facile, large-scale, and environmentally friendly liquid-exfoliation method to produce stable and high-concentration dispersions of mono- to few-layer black phosphorus (BP) nanosheets from bulk BP using nine ionic liquids. The prepared suspensions can stabilize without any obvious sedimentation and aggregation in ambient air for one month. In particular, the concentration (up to 0.95 mg mL(-1)) of BP nanoflakes obtained in 1-hydroxyethyl-3-methylimidazolium trifluoromethansulfonate ([HOEMIM][TfO]) is the highest reported for BP nanosheets dispersions. This work provides new opportunities for preparing atomically thin BP nanosheets in green, large-scale, and highly concentrated processes and achieving its in situ application.

Binary solvent systems consisting of biomassderived γ-valerolactone (GVL) and one cosolvent (e.g., water, ionic liquids, DMSO, and DMF) were developed as highly efficient systems for dissolution of various types of lignin. It was found that the content of cosolvent in GVL significantly affected the solubility of lignins. More importantly, we first concluded that the relationship between the solubility of lignin and hydrogen bond basicity parameter β value of solvents depends both on the solvent and on the lignin, which clarifies the existing dispute on this topic. Additionally, the dissolved lignin can be easily recovered by the addition of ethanol without its structure noticeably changing. The as-proposed systems are not only mild and highly efficient but also versatile and flexible (with different components and concentrations), thus adapting to the highly diversity of lignin.

In recent years, deep eutectic solvents (DESs) have attracted considerable attention. They have been applied in many fields such as dissolution and separation, electrochemistry, materials preparation, reaction, and catalysis. The DESs are generally formed by the hydrogen bonding interactions between hydrogen-bond donors (HBDs) and acceptors (HBAs). Knowledge of the thermal stability of DESs is very important for their application at high temperatures. However, there have been relatively few studies on the thermal stability of DESs. Herein, a systematic investigation on the thermal stability of 40 DESs was carried out using thermal gravimetric analysis (TGA), and the onset decomposition temperatures (Tonset) of these solvents were obtained. The most important conclusion drawn from this work is that the thermal behavior of DESs is quite different from that of ionic liquids. The anions or cations of ionic liquids decompose first, followed by the decomposition of the opposite ion at elevated temperatures. On the other hand, the DESs generally first decompose to HBDs and HBAs at high temperatures through the weakening of the hydrogen bond interactions. Subsequently, the HBDs with relatively low boiling points or poor stabilities undergo volatilization or decomposition; the HBAs also undergo volatilization or decomposition but at a higher temperature. For example, the most commonly used HBA choline chloride (ChCl) begins to decompose at around 250 °C. The hydrogen bond plays an important role in the thermal stability of DESs. It hinders the "escape" of molecules and requires greater energy to break than pure HBAs and HBDs, which causes the Tonset of DESs to shift to higher temperatures. Note that the thermal stability of HBDs has a crucial effect on the Tonset of DESs. The HBDs would decompose or volatilize first during TGA because of their relatively poor thermal stability or lower boiling points. The more stable the HBDs are, the greater would be the Tonset values of the corresponding DESs. Further, the effects of anions on HBAs, molar ratio of HBAs to HBDs, and heating rate in fast scan TGA have been discussed. As the heating rate increased, the TGA curves of DESs shifted to higher temperatures gradually, and the temperature hysteretic effect became prominent when the rate reached 10 °C•min −1 . From an industrial application point of view, there is an overestimation of the onset decomposition temperatures of DESs by Tonset, so the long-term stability of DESs was investigated at the end of the study. This study could help understand the thermal behavior of DESs (progressive decomposition) and provide guidance for designing DESs with appropriate thermal stability for practical applications.

High‐entropy materials, a new class of alloys that incorporate five or more principal elements into single‐phase crystal structures, have received considerable interest in materials science and engineering. Considering the tailored composition and disordered configuration, these high‐entropy materials may arouse functional synergism towards electrocatalysis. Here, a new strategy for preparing high‐entropy metal phosphides (HEMPs) was developed by a eutectic solvent method. The as‐prepared HEMP possessed a single metal phosphide phase with up to five homogenously distributed metal components. The versatile application of high‐entropy materials was highlighted by integrating the HEMP catalyst into a two‐electrode configuration for electrocatalytic water splitting.

A PEGylated deep eutectic solvent was developed and used for one step solvothermal synthesis of NiCo2S4 for efficient oxygen evolution reaction.