Synthetic nitrogen (N) fertilizers, especially urea (CO(NH2)2) with the highest nitrogen content, nourish crop production to underpin human life. The conventional urea synthesis relies on harsh industrial processes, which consumes approximately 2% of annual global energy. Instead, electrocatalysis is an emerging sustainable technology to produce urea at ambient conditions. Herein, by directly coupling nitrate (NO3 − ) with carbon dioxide (CO2) on an indium hydroxide catalyst, we realize highly selective urea electro-synthesis at ambient conditions. We derive that CO2 can suppress adverse hydrogen evolution reaction by transforming the surface semiconducting behaviour of the model catalyst in our work.The key step of C-N coupling initiates at an early stage through the reaction of *NO2 with *CO2 intermediates owing to the low energy barrier on {100} facets, hence the subsequent urea is synthesized with high Faradaic efficiency, nitrogen selectivity, and carbon selectivity, which reach 53.4%, 82.9% and ~100%, respectively. This work offers a desirable urea synthesis route and provides deep insights into the fundamental origin of C-N coupling for guiding other sustainable synthesis of indispensable chemicals.

Electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions provides an intriguing picture for the conversion of N into NH . However, electrocatalytic NRR mainly relies on metal-based catalysts, and it remains a grand challenge in enabling effective N activation on metal-free catalysts. Here we report a defect engineering strategy to realize effective NRR performance (NH yield: 8.09 μg h mg , Faradaic efficiency: 11.59 %) on metal-free polymeric carbon nitride (PCN) catalyst. Illustrated by density functional theory calculations, dinitrogen molecule can be chemisorbed on as-engineered nitrogen vacancies of PCN through constructing a dinuclear end-on bound structure for spatial electron transfer. Furthermore, the N-N bond length of adsorbed N increases dramatically, which corresponds to "strong activation" system to reduce N into NH . This work also highlights the significance of defect engineering for improving electrocatalysts with weak N adsorption and activation ability.

N fixation by the electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions is regarded as a potential approach to achieve NH production, which still heavily relies on the Haber-Bosch process at the cost of huge energy and massive production of CO . A noble-metal-free Bi V O /CeO hybrid with an amorphous phase (BVC-A) is used as the cathode for electrocatalytic NRR. The amorphous Bi V O contains significant defects, which play a role as active sites. The CeO not only serves as a trigger to induce the amorphous structure, but also establishes band alignment with Bi V O for rapid interfacial charge transfer. Remarkably, BVC-A shows outstanding electrocatalytic NRR performance with high average yield (NH : 23.21 μg h mg , Faradaic efficiency: 10.16 %) under ambient conditions, which is superior to the Bi V O /CeO hybrid with crystalline phase (BVC-C) counterpart.

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Aqueous Al-ion batteries (AAIBs) are the subject of great interest due to the inherent safety and high theoretical capacity of aluminum. The high abundancy and easy accessibility of aluminum raw materials further make AAIBs appealing for grid-scale energy storage. However, the passivating oxide film formation and hydrogen side reactions at the aluminum anode as well as limited availability of the cathode lead to low discharge voltage and poor cycling stability. Here, we proposed a new AAIB system consisting of an Al x MnO 2 cathode, a zinc substrate-supported Zn−Al alloy anode, and an Al(OTF) 3 aqueous electrolyte. Through the in situ electrochemical activation of MnO, the cathode was synthesized to incorporate a two-electron reaction, thus enabling its high theoretical capacity. The anode was realized by a simple deposition process of Al 3+ onto Zn foil substrate. The featured alloy interface layer can effectively alleviate the passivation and suppress the dendrite growth, ensuring ultralong-term stable aluminum stripping/ plating. The architected cell delivers a record-high discharge voltage plateau near 1.6 V and specific capacity of 460 mAh g −1 for over 80 cycles. This work provides new opportunities for the development of highperformance and low-cost AAIBs for practical applications.

2D nanomaterials provide numerous fascinating properties, such as abundant active surfaces and open ion diffusion channels, which enable fast transport and storage of lithium ions and beyond. However, decreased active surfaces, prolonged ion transport pathway, and sluggish ion transport kinetics caused by self‐restacking of 2D nanomaterials during electrode assembly remain a major challenge to build high‐performance energy storage devices with simultaneously maximized energy and power density as well as long cycle life. To address the above challenge, porosity (or hole) engineering in 2D nanomaterials has become a promising strategy to enable porous 2D nanomaterials with synergetic features combining both 2D nanomaterials and porous architectures. Herein, recent important progress on porous/holey 2D nanomaterials for electrochemical energy storage is reviewed, starting with the introduction of synthetic strategies of porous/holey 2D nanomaterials, followed by critical discussion of design rule and their advantageous features. Thereafter, representative work on porous/holey 2D nanomaterials for electrochemical capacitors, lithium‐ion and sodium‐ion batteries, and other emerging battery technologies (lithium‐sulfur and metal‐air batteries) are presented. The article concludes with perspectives on the future directions for porous/holey 2D nanomaterial in energy storage and conversion applications.

Research on 2D nanomaterials is rising to an unprecedented height and will continue to remain a very important topic in materials science. In parallel with the discovery of new candidate materials and exploration of their unique characteristics, there are intensive interests to rationally control and tune the properties of 2D nanomaterials in a predictable manner. Considerable attention is focused on modifying these materials structurally or engineering them into designed architectures to meet requirements for specific applications. Recent advances in such structural engineering strategies have demonstrated their ability to overcome current material limitations, showing great promise for promoting device performance to a new level in many energy-related applications. Existing in many forms, these strategies can be categorized based on how they intrinsically or extrinsically alter the pristine structure. Achieved through various synthetic routes and practiced in a range of different material systems, they usually share common descriptors that predestine them to be effective in certain circumstances. Therefore, understanding the underlying mechanism of these strategies to provide fundamental insights into structural design and property tailoring is of critical importance. Here, the most recent development of structural engineering of 2D nanomaterials and their significant effects in energy storage and catalysis technologies are addressed.

Metal–organic frameworks (MOFs) have obtained increasing attention as a kind of novel electrode material for energy storage devices.