Light to H₂O₂ : The nanosheet photocatalysts containing double defects were prepared by the calcination method. The microstructure, photoelectric properties, and photocatalytic performance of the materials were systematically investigated. The −C≡N groups promote the adsorption of H⁺ and the S-defects provide the active center for the adsorption and activation of O₂.

Abstract

In this work, the graphitic carbon nitride with −C≡N defects and S-defects (N₂−SCN-4) was constructed. The H₂O₂ production efficiency of N₂−SCN-4 was 1423.3 μmol g⁻¹ h⁻¹ under the visible light (λ≥420 nm) irradiation, which was 15.4 times that of pristine g-C₃N₄. The −C≡N groups promote the adsorption of H⁺ and the S-defects provide the active center for the adsorption and activation of O₂. Furthermore, the surface morphology, microstructure, and photoelectric chemical properties of samples were investigated by a series of characterizations, and the response range of N₂−SCN-4 to visible light increases obviously. Meanwhile, the efficiency of photo-produced charge separation and the selectivity of H₂O₂ production were discussed in detail. The experimental and characterization results confirmed that the charge separation efficiency and the selectivity of the 2e⁻ O₂ reduction reaction (ORR) were improved under the synergistic effect of the double defects. This work provides a strategy for improving the photocatalytic performance of photocatalysts.

The selection and design of new electrode materials for energy conversion and storage are critical for improved performance, cost reduction, and mass manufacturing. A bifunctional anode with high catalytic activity and extended cycle stability is crucial for rechargeable lithium-ion batteries and direct borohydride fuel cells. Herein, a high entropy novel three-dimensional structured electrode with Pr-doped hollow NiFeP nanoflowers inlaid on N-rGO was prepared via a simple hydrothermal and self-assembly process. For optimization of Pr content, three (0.1, 0.5, and 0.8) different doping ratios were investigated. A lithium-ion battery assembled with NiPr0.5FeP/N-rGO electrode achieved an outstanding specific capacity of 1618.81 mAh g−1 at 200 mA g−1 after 100 cycles with 99.3% Coulombic efficiencies. A prolonged cycling stability of 1025.49 mAh g−1 was maintained even after 1000 cycles at 500 mA g−1. In addition, a full cell battery with NiPr0.5FeP/N-rGO ∥ LCO (Lithium cobalt oxide) delivered a promising cycling performance of 525.8 mAh g−1 after 200 cycles at 150 mA g−1. Subsequently, the NiPr0.5FeP/N-rGO electrode in a direct borohydride fuel cell showed the highest peak power density of 93.70 mW cm−2 at 60 °C. Therefore, this work can be extended to develop advanced electrode for next-generation energy storage and conversion systems.

Degradation mechanisms in LiTFSI/water solutions, which are well-known water-in-salt electrolytes (WISEs), are evidenced through an accelerated radiolysis approach. Aging mechanisms depend strongly on the molality of the salt and on the interactions and competition between the reactivities of water and the anions. The main aging products determined by radiolysis are consistent with the ones observed electrochemically.

Abstract

Aqueous solutions are crucial to most domains in biology and chemistry, including in energy fields such as catalysis and batteries. Water-in-salt electrolytes (WISEs), which extend the stability of aqueous electrolytes in rechargeable batteries, are one example. While the hype for WISEs is huge, commercial WISE-based rechargeable batteries are still far from reality, and there remain several fundamental knowledge gaps such as those related to their long-term reactivity and stability. Here, we propose a comprehensive approach to accelerating the study of WISE reactivity by using radiolysis to exacerbate the degradation mechanisms of concentrated LiTFSI-based aqueous solutions. We find that the nature of the degradation species depends strongly on the molality of the electrolye, with degradation routes driven by the water or the anion at low or high molalities, respectively. The main aging products are consistent with those observed by electrochemical cycling, yet radiolysis also reveals minor degradation species, providing a unique glimpse of the long-term (un)stability of these electrolytes.

The refinement of biomass, particularly lignin, for the production of chemicals as a solution to the energy crisis, has been substantiated as a potentially promising technology. The effective amalgamation of photocatalytic technology with biomass refining has received considerable attention recently. Nonetheless, the current research landscape is heavily concentrated on lignin molecular models, with little attention being paid to the study of actual lignin. This Review highlights recent progress in the photoreforming of actual lignin for the production of energy or chemicals.

Abstract

Photoreforming of lignocellulosic biomass to simultaneously produce gas fuels and value-added chemicals has gradually emerged as a promising strategy to alleviate the fossil fuels crisis. Compared to cellulose and hemicellulose, the exploitation and utilization of lignin via photoreforming are still at the early and more exciting stages. This Review systematically summarizes the latest progress on the photoreforming of lignin-derived model components and “real” lignin, aiming to provide insights for lignin photocatalytic valorization from fundamental to industrial applications. Considering the complexity of lignin physicochemical properties, related analytic methods are also introduced to characterize lignin photocatalytic conversion and product distribution. We finally put forward the challenges and perspective of lignin photoreforming, hoping to provide some guidance to valorize biomass into value-added chemicals and fuels via a mild photoreforming process in the future.

Scalable chemical processes have been used to convert biorenewable β-pinene into 4-isopropenylcyclohexanone (4-IPEC), which is then used as a feedstock to prepare bioderived versions of the commonly prescribed painkillers, paracetamol and ibuprofen.

Abstract

Scalable processes have been developed to convert β-pinene into 4-isopropenylcyclohexanone, which is then used as a feedstock for the divergent synthesis of sustainable versions of the common painkillers, paracetamol and ibuprofen. Both synthetic routes use Pd⁰ catalysed reactions to aromatize the cyclohexenyl rings of key intermediates to produce the benzenoid ring systems of both drugs. The potential of using bioderived 4-hydroxyacetophenone as a drop-in feedstock replacement to produce sustainable aromatic products is also discussed within a terpene biorefinery context.

Advanced failure warning: Combining in-line real-time multi-sine electrochemical impedance spectroscopy with selectivity and voltage data builds a framework for stable electrolysis enabling early failure detection and prevention.

Abstract

The electrochemical CO₂ reduction reaction (CO₂RR) to fuels and feedstocks presents an opportunity to decarbonize the chemical industry, and current electrolyzer performance levels approach commercial viability. However, stability remains below that required, in part because of the challenge of probing these electrolyzer systems in real time and the challenge of determining the root cause of failure. Failure can result from initial conditions (e. g., the over- or under-compression of the electrolyzer), gradual degradation of components (e. g., cathode or anode catalysts), the accumulation of products or by-products, or immediate changes such as the development of a hole in the membrane or a short circuit. Identifying and mitigating these assembly-related, gradual, and immediate failure modes would increase both electrolyzer lifetime and economic viability of CO₂RR. We demonstrate the continuous monitoring of CO₂RR electrolyzers during operation via non-disruptive, real-time electrochemical impedance spectroscopy (EIS) analysis. Using this technique, we characterise common failure modes - compression, salt formation, and membrane short circuits - and identify electrochemical parameter signatures for each. We further propose a framework to identify, predict, and prevent failures in CO₂RR electrolyzers. This framework allowed for the prediction of anode degradation ~11 hours before other indicators such as selectivity or voltage.

Innovative Fe[Fe(CN)₅NO] (PBN) cathode material effectively eliminates the negative effects of crystal water in Prussian blue analogues (PBA) for sodium-ion batteries. PBN demonstrates lower crystal water content and volume expansion compared to traditional PBA. The N=O bond in PBN also enhances the diffusion potential of Na⁺ ions, leading to improved reversible capacity and cycling stability.

Abstract

Prussian blue analogues (PBAs) are promising cathode materials for sodium-ion batteries (SIBs) due to their tunable chemistry, open channel structure, and low cost. However, excessive crystal water and volume expansion can negatively impact the lifetime of actual SIBs. In this study, a novel iron nitroprusside: Fe[Fe(CN)₅NO] (PBN) was synthesized to effectively eliminate the detrimental effects of crystal water on the reversible capacity and cycling stability of PBA materials. Experiments and DFT calculations demonstrated that PBN has lower crystal water and volume expansion compared to Fe[Fe(CN)₆] (PB). Also, the N=O bond in PBN significantly reduces the diffusion potential of Na⁺ in the skeleton. Without any modification, the cathode material exhibited a capacity of up to 148.6 mAh g⁻¹ at 50 mA g⁻¹ as well as maintained 102.9 mAh g⁻¹ after 200 cycles. This work expands our knowledge of the crystal structure of PBA cathode materials and facilitates the rational design of high-quality PBA cathodes for SIBs.

Poisoning to promote? Poisoning of cathode catalyst surface by CO induces suppression of hydrogen evolution reaction (HER) and drastically boosts the Faradaic efficiency of NO reduction to NH₃ in a polymer electrolyte membrane (PEM) cell. The promotional effects towards selective ammonia formation is dependent on the type of metals which uniquely interact with CO with specific surface sites driving HER and/or NO reduction.

Abstract

Direct electroreduction of nitric oxide offers a promising avenue to produce valuable chemicals, such as ammonia, which is an essential chemical to produce fertilizers. Direct ammonia synthesis from NO in a polymer electrolyte membrane (PEM) electrolyzer is advantageous for its continuous operation and excellent mass transport characteristics. However, at a high current density, the faradaic efficiency of NO electroreduction reaction is limited by the competing hydrogen evolution reaction (HER). Herein, we report a CO-mediated selective poisoning strategy to enhance the faradaic efficiency (FE) towards ammonia by suppressing the HER. In the presence of only NO at the cathode, Pt/C and Pd/C catalysts showed a lower FE towards NH₃ than to H₂ due to the dominating HER. Cu/C catalyst showed a 78 % FE towards NH₃ at 2.0 V due to the stronger binding affinity to NO* compared to H*. By co-feeding CO, the FE of Cu/C catalyst towards NH₃ was improved by 12 %. More strikingly, for Pd/C, the FE towards NH₃ was enhanced by 95 % with CO co-feeding, by effectively suppressing HER. This is attributed to the change of the favorable surface coverage resulting from the selective and competitive binding of CO* to H* binding sites, thereby improving NH₃ selectivity.

Dual-ion batteries have been considered as a competitive energy storage device. However, owing to the lack of the suitable high-capacity density and rapid-charging kinetics electrode materials, designing a cost-effective and high performance dual-ion battery is still a great challenge. Herein, an ultrahigh-capacity dual-ion battery is constructed based on the SnS2-MoS2@CNTs heterojunction anode and high crystallinity free-standing graphite paper serves as cathode. The SnS2-MoS2@CNTs heterojunction consisted of ultrathin nanosheets is prepared via a facile two-step hydrothermal method, and shows flower-like morphology and high crystallinity. Benefiting from the unique design concept, the Graphite paper/SnS2-MoS2@CNTs dual-ion battery delivers a high capacity of 274.2 mA h g-1 at 100 mA g-1 and keeps an outstanding capacity retention of 95% after 300 cycles under 400 mA g-1. Even at a high current density of 2 A g-1, the battery still retains a considerable capacity of 112.3 mA h g-1. More importantly, the battery shows an extremely low self-discharge of 0.006% h-1 after resting for 24 h. The characterization of SEM and XRD further demonstrate the excellent cycling stability and good reversibility. Consequently, this constructed dual-ion battery could be a promising energy storage device and provide new insight for the design of high-performance dual-ion batteries.

Cellulose-derived hydrogel: Dispersion of feedstock determines material performance. This review summarizes the currently developed solvents and modification methods that not only increase the dissolution of cellulose, but also are the strategies for forming cellulose-based hydrogels. Also, the “reinforcement” of cellulose-based hydrogels by physical and chemical techniques is introduced.

Abstract

The cellulose-based hydrogel has occupied a pivotal position in almost all walks of life. However, the native cellulose can not be directly used for preparing hydrogel due to the complex non-covalent interactions. Some literature has discussed the dissolution and modification of cellulose but has yet to address the influence of the pretreatment on the as-prepared hydrogels. Firstly, the “touching” of cellulose by derived and non-derived solvents was introduced, namely, the dissolution of cellulose. Secondly, the “conversion” of functional groups on the cellulose surface by special routes, which is the modification of cellulose. The above-mentioned two parts were intended to explain the changes in physicochemical properties of cellulose by these routes and their influences on the subsequent hydrogel preparation. Finally, the “reinforcement” of cellulose-based hydrogels by physical and chemical techniques was summarized, viz., improving the mechanical properties of cellulose-based hydrogels and the changes in the multi-level structure of the interior of cellulose-based hydrogels.