Delamination of layer materials into two-dimensional single-atom sheets has induced exceptional physical properties, including large surface area, ultrahigh intrinsic carrier mobility, pronounced changes in the energy band structure, and other properties. Here, atomically thin mesoporous nanomesh of graphitic carbon nitride (g-C3N4) is fabricated by solvothermal exfoliation of mesoporous g-C3N4 bulk made from thermal polymerization of freeze-drying assembled Dicyandiamide nanostructure precursor. With the unique structural advantages for aligned energy levels, electron transfer, light harvesting, and the richly available reaction sites, the as-prepared monolayer of mesoporous g-C3N4 nanomesh exhibits a superior photocatalytic hydrogen evolution rate of 8510 μmol h(-1) g(-1) under λ > 420 nm and an apparent quantum efficiency of 5.1% at 420 nm, the highest of all the metal-free g-C3N4 nanosheets photocatalysts.

A capacity-recoverable zinc-ion micro-supercapacitor with high energy and power density is developed.

Melt blending poly(L-lactide) (PLLA) with various biodegradable polymers has been thought to be the most economic and effective route to toughen PLLA without compromising its biodegradability. Unfortunately, only very limited improvement in notched impact toughness can be achieved, although most of these blends show significant enhancement in tensile toughness. In this work, biodegradable poly(ε-caprolactone) (PCL) was used as an impact modifier to toughen PLLA and a nucleating agent was utilized to tailor the crystallization of PLLA matrix. Depending on the nucleating agent concentrations in the matrix and mold temperatures in injection molding, PLLA/PCL blends with a wide range of matrix crystallinity (10-50%) were prepared by practical injection molding. The results show that there is a linear relationship between PLLA matrix crystallinity and impact toughness. With the increase in PLLA crystalline content, toughening becomes much easier to achieve. PLLA crystals are believed to provide a path for the propagation of shear yielding needed for effective impact energy absorption, and then, excellent toughening effect can be obtained when these crystals percolate through the whole matrix. This investigation provides not only a new route to prepare sustainable PLLA products with good impact toughness but also a fresh insight into the importance of matrix crystallization in the toughening of semicrystalline polymers with a flexible polymer.

Electrocatalytic water splitting is a sustainable way to produce hydrogen energy, but the oxygen evolution reaction (OER) at the anode has sluggish kinetics and low energy conversion efficiency, which is the major bottleneck for large-scale hydrogen production. The design and synthesis of robust and low-cost OER catalysts are crucial for the OER. NiCo-based electrocatalysts have suitable atomic and electronic structures, and show high activity and stability during the OER process. Recently, significant progress has been made in regulating the structure and composition of NiCo-based catalysts and understanding the nature of catalysis, especially the OER mechanism, catalytic active sites, and structure–activity relationship. In this work, we summarized and discussed the latest development of NiCo-based electrocatalysts in the OER, with particular emphasis on catalyst design and synthesis, strategies for boosting OER performance, and understanding the nature of catalysis from experimental and theoretical perspectives. The OER mechanism, some activity descriptors, and atomic and electronic structure–activity relationships based on NiCo-based electrocatalysts are unveiled. Finally, some challenges and futuristic outlooks for improving the performance of NiCo-based electrocatalysts are proposed, and we hope this review can provide guidance for the design of more efficient NiCo-based electrocatalysts.

Spontaneous electricity generation through water evaporation is becoming a hot research area. However, low power output, limited material availability, and unscalable fabrication largely hinder its wide applications. Here, we report scalable painting and blade coating approaches for the mass production of flexible hydroelectric films (HEFs) based on solid oxides (e.g., Al2O3), which are of tolerance to mechanical deformation and are compatible with three-dimensional diverse configuration. The electricity power is generated continuously and can last for more than 10 days in ambient conditions. A single HEF unit is capable of supplying an output voltage of more than 2.5 V and even up to 4.5 V at specific conditions. The accumulative energy output can be tuned conveniently by means of series/parallel connections or size control to meet the practical needs of commercial electronics. A family of solid oxides has been verified to have the ability for water evaporation-induced electricity generation, which offers considerable room for the development of high-performance energy-supplying devices.