EnergyChem最新文献

Semiconductor photocatalysis is considered as a cutting-edge research topic for the production of value-added fuels and chemicals to confront the global energy crisis. In order to improve the solar-to-chemical conversion efficiency of pristine semiconductors, combining them with cocatalysts to form heterostructures has been extensively investigated. Among studied formulations, bimetallic nanoparticles (NPs), featuring enhanced light harvesting, efficient capture of photogenerated electrons and abundant surface active sites are ideal cocatalysts to improve the photocatalytic performance of semiconductor-based photocatalysts. In this review, we begin with a concise overview of representative synthesis and characterization methods of bimetallic NPs. Then, we predominantly summarize the typical applications of semiconductor/bimetallic NPs-based composites in photoredox catalysis, including hydrogen evolution, carbon dioxide reduction, selective organic synthesis and environmental remediation. In particular, we highlight the regulatory effects of parameters of bimetallic NPs (composition, structure, morphology, size, atomic arrangement, loading position, etc.) on the photocatalytic activity and selectivity. Finally, the remaining challenges and future perspectives for the utilization of bimetallic NPs in photoredox catalysis are discussed and anticipated to stimulate the sparkling ideas in the construction of high-efficiency semiconductor/bimetallic NPs-based photocatalytic systems.

Organic solar cells have achieved rapid development over the last few years, benefitting from the emerging of new non-fullerene acceptors (NFAs). The reported power conversion efficiency of OSCs has achieved over 18% up to now, however, the inferior stability issue restricts its commercialization, which stimulates the interest of scientists to explore it in-depth as well. Thus, we discuss the mechanisms of the instability in OSC devices, comprehensively summarize the progress of OSC stability in recent years and propose a series of solutions that improve the stability in this review. Although the highly-stable OSCs with extrapolated lifetime over several decades have been reported, the biggest drawback of them is the insufficient PCE. Thereby, investigating efficient OSCs with high-stability is required. We expect this review can provide some guidelines to address the instability of OSCs for feasible commercialization in the future.

The sufficient supply of energy remains one of the most important challenges for a sustainable development of our society. In this respect, capturing sunlight energy by photocatalytic reduction of the greenhouse gas CO₂ is interesting. In a more general way, the smart use of CO₂ as C₁-feedstock and its conversion to valuable carbon-based materials and energy sources can be the basis to establish a closed-CO₂ cycle. This review summarizes recent advances in photocatalytic utilization of CO₂ catalyzed by most prominent TiO₂ based systems. The influences of different structures (i.e. crystal phase, morphology, vacancies, and defects), co-catalysts, and reaction conditions onto the catalyst performance are specifically highlighted. Furthermore, the reader attention is drawn to the oxidation counter reaction, which has been often neglected in the past.

Lithium ion batteries (LIBs) have become an indispensable part of human development and our lives, from spaceships to deep-sea submersibles as well as ordinary electronics. Since it was proposed in the 1970s and commercialized in 1991, LIBs have been pursuing higher energy, higher power, higher safety and higher durability. Therefore, there is an urgent need to develop more efficient anode materials to overcome the capacity and rate bottlenecks of commercial graphite. Oxide anodes stand out in terms of high capacity and working potential, e.g., Li₄Ti₅O₁₂ has been a high-performance safe anode material. Yet developed early, most of oxide anodes suffer from low conductivity, low initial coulombic efficiency and large volume change during lithium/delithiation process. Recently, defect engineering has significantly improved the performance of oxide anodes and alleviated the above problems. In this review, we present the fundamentals, challenges and recent research progress on defective oxide anodes of LIBs. Firstly, the development history of LIBs and oxide anode is briefly introduced. Then, the definition, classification, preparation method, structure-function relationship between defect structure and electrochemical performance are introduced in detail, as well as the development perspective of defect oxide anode.

Different from other carbon allotropes, graphdiyne (GDY) features topological sp- and sp²-hybridized carbon atoms. With the unique structural advances, a charming electronic behavior has been presented by GDY, which has shown great improvement for various energy-related fields. Inspired by this, it is time to summarize the structure-induced property enhancement. Firstly, different stacking configurations in GDY can induce specific electronic properties, bringing promising energy application. Secondly, uniform pores provide enough sites for anchoring atoms and nanoparticles, enriching the diversity of materials. Thirdly, the sufficient alkynyl groups offer active sites for doping and grafting, providing possibilities for the precise design at the molecular level. Lastly, we propose some perspectives for future trends on GDY. Through this review, we hope to provide a guideline for rational design on GDY-based materials and reveal the structure-performance relationship between functionalized GDY and energy conversion/storage.

The field of bulk heterojunction (BHJ) organic photovoltaics (OPVs) or solar cells (OSCs) has experienced a dramatic advance toward a competitive technology reflecting the introduction of new materials, tuning of materials combinations, and optimization of the device architecture. Thus, binary BHJ OSCs with power conversion efficiencies surpassing 18% have been demonstrated. In this review we discuss recent developments in the area of π-conjugated small-molecule and polymeric semiconductors for organic BHJ-OSCs focusing on both electron-donor (hole-transporting) and electron-acceptor (electron-transporting) semiconductors developed during the past three years. Thus, several families of semiconductor materials including donor-acceptor (D-A) polymers, fullerene, and non-fullerene acceptors (NFAs) are reviewed including their combination for polymer-fullerene, donor polymer-NFA, all-small molecule, and all-polymer solar cells.

Capacitive deionization (CDI) is regarded as a novel, low-cost, and environmentally friendly technique that plays a critical role in desalination and water treatment. Although much progress has been achieved, the development of better CDI technologies, especially through the design and synthesis of various porous carbonaceous materials with enhanced CDI performance, continues to attract increasing interest within the scientific fraternity. Considering that previous traditional porous carbons might suffer from deficient salt adsorption capacity, the nitrogenization of porous carbons, which brings new opportunities for CDI applications, has emerged as an effective strategy to modify the surface characteristics of porous carbons and ultimately improve their CDI performance. This review summarizes the recent significant breakthroughs on the construction of NCs, including in situ doping and post-treatment strategies, and their practices in the field of CDI to impart a comprehensive understanding of the strategic evolution of the synthetic approaches to nitrogen-doped carbons (NCs) with remarkable CDI characteristics. We present an exhaustive analysis of newly synthesized NCs and the impact of their compositional and structural features on their CDI performance; further, we highlight a special emphasis on the possible role of nitrogen dopants in the CDI process. In addition to elucidating the state-of-the-art CDI applications, we address the remaining challenges, and finally, the possible direction for the use of NCs for CDI is described to provide some useful clues for future developments in this promising field.

Porous aromatic frameworks (PAFs) are amorphous porous materials that are known for their large surface area, versatile structure, and high thermal/chemical stability. PAFs are constructed via a bottom-up approach from rigid organic building units that have a predesigned geometry and are connected through irreversible C−C bonds. Due to their intriguing and tailorable structures, PAFs are widely deployed in catalysis, ion/molecule storage, and many other valuable applications. This review summarizes the recent progress on PAFs and PAF derivatives, including their design, synthesis, and applications. We conduct a detailed correlation investigation between the structural and chemical features of PAFs and their potential functions. The significant advantages (and disadvantages) and opportunities of PAFs are also discussed for the development of next-generation porous materials in the future for practical applications.

Ammonia is one of the most important chemicals in modern world for food supply, yet its production through nitrogen reduction is mainly relied on the Haber–Bosch process, requiring rigid reaction conditions including high temperature and pressure. Recently, electrocatalytic nitrogen fixation into ammonia has provoked wide attention due to its capability to be performed under mild condition, with the electricity as the only power input. Nevertheless, the conventional metal-based electrocatalysts normally suffers from their difficulty in balancing the competitive reactions of nitrogen adsorption/activation and hydrogen generation, hampering the ammonia production efficiency. Lately, metal-free electrocatalysts have turned up as a promising candidate for such an approach due to their highly controllable surface-structure and relatively sluggish hydrogen generation activity. In this review, we summarize recent progress in electrocatalytic nitrogen reduction reaction using metal-free electrocatalysts, with the particular emphasis on their electronic structure and microstructure modulations for ameliorating N₂ adsorption/activation and electron transfer. Finally, the challenges and future directions of metal-free catalyst for nitrogen reduction reaction are given.

Photoelectrochemical (PEC) device integrated by solar absorber and catalyst is an economically viable solution for storing the solar energy into the fuel, synthesizing the chemical production, and purifying the environment. However, the degradation of semiconductor-based photoelectrodes during PEC reactions is one of the largest limitations for the application of PEC devices. Facing this challenge, the most prevailing strategy is to construct the protection layer on the surface of semiconductor for insulating the semiconductor from the electrolyte. The development of defect engineering in the protection layer is used to further addresses the issues from the introduction of new layer, including light transmission, charge transfer, interfacial recombination and surface activity. This review aims to discuss recent advances in the defect engineering of protection layer for PEC devices. The types, characterization, role and utilization of the defects in the protection layer are discussed and summarized. Finally, the critical challenges and future perspective towards the development of the defect engineering of protection layer for PEC devices are analyzed.