A Cost‐Efficient Bifunctional Ultrathin Nanosheets Array for Electrochemical Overall Water Splitting

The design of cost‐efficient earth‐abundant catalysts with superior performance for the electrochemical water splitting is highly desirable. Herein, a general strategy for fabricating superior bifunctional water splitting electrodes is reported, where cost‐efficient earth‐abundant ultrathin Ni‐based nanosheets arrays are directly grown on nickel foam (NF). The newly created Ni‐based nanosheets@NF exhibit unique features of ultrathin building block, 3D hierarchical structure, and alloy effect with the optimized Ni₅Fe layered double hydroxide@NF (Ni₅Fe LDH@NF) exhibiting low overpotentials of 210 and 133 mV toward both oxygen evolution reaction and hydrogen evolution reaction at 10 mA cm^?2 in alkaline condition, respectively. More significantly, when applying as the bifunctional overall water splitting electrocatalyst, the Ni₅Fe LDH@NF shows an appealing potential of 1.59 V at 10 mA cm^?2 and also superior durability at the very high current density of 50 mA cm^?2.     

Advanced Nanostructured Anode Materials for Sodium‐Ion Batteries

Sodium–ion batteries (NIBs), due to the advantages of low cost and relatively high safety, have attracted widespread attention all over the world, making them a promising candidate for large‐scale energy storage systems. However, the inherent lower energy density to lithium–ion batteries is the issue that should be further investigated and optimized. Toward the grid‐level energy storage applications, designing and discovering appropriate anode materials for NIBs are of great concern. Although many efforts on the improvements and innovations are achieved, several challenges still limit the current requirements of the large‐scale application, including low energy/power densities, moderate cycle performance, and the low initial Coulombic efficiency. Advanced nanostructured strategies for anode materials can significantly improve ion or electron transport kinetic performance enhancing the electrochemical properties of battery systems. Herein, this Review intends to provide a comprehensive summary on the progress of nanostructured anode materials for NIBs, where representative examples and corresponding storage mechanisms are discussed. Meanwhile, the potential directions to obtain high‐performance anode materials of NIBs are also proposed, which provide references for the further development of advanced anode materials for NIBs.     

Public awareness of the environmental impact and management of carbon dioxide capture,utilization and storage technology: the views of educated people in China

Carbon dioxide capture, utilization and storage (CCUS) is regarded as an important carbon emissions reduction technology response to climate change. Though some full-chain CCUS pilot projects have operated in China, many barriers exist when stepping up to commercial applications, including significant negative perceptions of the environmental risk of CCUS. Therefore, to tailor constructive training or outreach programs for public acceptance of CCUS in China, a large national survey of public perceptions of CCUS technology was conducted in 2013. The questionnaire contained four themes focusing on people with a tertiary education. Six hundred paper–pencil questionnaires were dispatched to 22 universities/enterprises across 19 provinces and 2 municipalities, with a response rate of 95%. The results show that 91.4% of the participants agreed that the earth was experiencing climate change, and 74.3% were interested in low-carbon technologies, but while 22% had heard of CCUS, although with limited knowledge, only 3.6% had a good understanding of the technology. The results from the second part of the questionnaire show that 80.4% of participants believed that CCUS may help to mitigate the impacts of global warming, but the “Not in My Back Yard” (NIMBY) phenomenon was obvious from the location-based objections to transportation and storage processes. In addition, ten listed CCUS environmental management policies received extensive recognition from the participants, and about half of the participants considered that the related government departments should be responsible for environmental management as a first priority. The survey also indicates that the most trusted sources through which the survey participants obtain CCUS information are academic journals and textbooks, television, radio and newspapers, expert lectures and brochures on CCUS demonstration projects. According to the survey of public awareness of the environmental impact and management of CCUS technology in China, CCUS technology rates well for environmental benefits, but high environmental risk perceptions of CCUS lead to a lower acceptance of this carbon emissions reduction technology.     

Proline-derived in situ synthesis of nitrogen-doped porous carbon nanosheets with encaged Fe2O3@Fe3C nanoparticles for lithium-ion battery anodes

The homogeneous incorporation of heteroatoms into two-dimensional C nanostructures, which leads to an increased chemical reactivity and electrical conductivity as well as enhanced synergistic catalysis as a conductive matrix to disperse and encapsulate active nanocatalysts, is highly attractive and quite challenging. In this study, by using the natural and cheap hydrotropic amino acid proline—which has remarkably high solubility in water and a desirable N content of ~12.2 wt.%—as a C precursor pyrolyzed in the presence of a cubic KCl template, we developed a facile protocol for the large-scale production of N-doped C nanosheets with a hierarchically porous structure in a homogeneous dispersion. With concomitantly encapsulated and evenly spread Fe₂O₃ nanoparticles surrounded by two protective ultrathin layers of inner Fe₃C and outer onion-like C, the resulting N-doped graphitic C nanosheet hybrids (Fe₂O₃@Fe₃C-NGCNs) exhibited a very high Li-storage capacity and excellent rate capability with a reliable and prolonged cycle life. A reversible capacity as high as 857 mAh•g^–1 at a current density of 100 mA•g^–1 was observed even after 100 cycles. The capacity retention at a current density 10 times higher—1,000 mA•g^–1—reached 680 mAh•g^–1, which is 79% of that at 100 mA•g^–1, indicating that the hybrids are promising as anodes for advanced Li-ion batteries. The results highlight the importance of the heteroatomic dopant modification of the NGCNs host with tailored electronic and crystalline structures for competitive Li-storage features.