In response to serious ecological and environmental problems worldwide, a novel graphene oxide (GO) induction method for the in situ synthesis of GO/metal organic framework (MOF) composites (Ni-BTC@GO) for supercapacitors with excellent performance is presented in this study. For the synthesis of the composites, 1,3,5-benzenetricarboxylic acid (BTC) is used as an organic ligand due to its economic advantages. The optimum amount of GO is determined by a comprehensive analysis of morphological characteristics and electrochemical tests. 3D Ni-BTC@GO composites show a similar spatial structure to that of Ni-BTC, revealing that Ni-BTC could provide an effective framework and avoid GO aggregation. The Ni-BTC@GO composites have a more stable electrolyte-electrode interface and an improved electron transfer route than pristine GO and Ni-BTC. The synergistic effects of GO dispersion and Ni-BTC framework on electrochemical behavior are determined, where Ni-BTC@GO 2 achieves the best performance in energy storage performance. Based on the results, the maximum specific capacitance is 1199 F/g at 1 A/g. Ni-BTC@GO 2 has an excellent cycling stability of 84.47% after 5000 cycles at 10 A/g. Moreover, the assembled asymmetric capacitor exhibits an energy density of 40.89 Wh/kg at 800 W/kg, and it still remains at 24.44 Wh/kg at 7998 W/kg. This material is expected to contribute to the design of excellent GO-based supercapacitor electrodes.

NiFe-layered double hydroxides (NiFe-LDHs), as promising electrocatalysts, have received significant research attention for hydrogen and oxygen generation through water splitting. However, the slow oxidation kinetics of NiFe-LDH, due to the limited number of active sites and the low conductivity, hinders the improvement of the water-splitting efficiency. Therefore, to overcome the obstacles, two-dimensional (2D) SnS was first explored to tailor the prepared NiFe-LDH via the hydrothermal method. A NiFe-LDH/SnS heterojunction is built, which is observed from the microstructural investigations. SnS incorporation could greatly improve the conductivity of the NiFe-LDH sheets, which was reflected by the reduced charge transfer resistance. Moreover, SnS layers modulated the electronic environment around the active sites, favoring the adsorption of intermediates during the oxygen evolution reaction (OER) process, which was verified by density functional theory calculations. A synergistic effect induced by the NiFe-LDH/SnS heterostructure promoted the OER activities in electrical, electronic, and energetic aspects. Consequently, the as-prepared NiFe-LDH/SnS electrocatalyst greatly improved the electrocatalytic performance, exhibiting 20% and 27% reductions in the overpotential and Tafel slope compared with those of pristine NiFe-LDH, respectively. The results provide a strategy for regulating NiFe-based electrocatalysts by using emerging 2D materials to enhance water-splitting efficiency.

The discharge of organic pollutants by the textile and dyeing industries presents an escalating threat to aquatic environments, necessitating the development of effective remediation strategies. This study introduces the utilization of graphite-like structured activated carbon (AC), derived from highland barley straw-a biomass unique to the Plateau regions of China, including Tibet, Qinghai, and Gansu-as a support material for the TiO₂ catalyst. TiO₂/AC composites with different TiO₂ loadings were synthesized by ultrasonic impregnation. The TiO₂/AC composites were found to be polycrystalline materials composed of anatase and rutile phases. The TiO₂ nanoparticles are well-dispersed over the surface of the AC. The photocatalytic activity of these composites was evaluated through their capacity to degrade a methylene blue (MB) solution upon irradiation. It was observed that the inclusion of TiO₂ increases the number of adsorption sites and active sites for methylene blue, with the photocatalytic activity being notably higher at a 3-wt% TiO₂ loading, achieving a remarkable 99.6 % degradation efficiency for 100 mg/L MB within 100 min. The experimental kinetic data for the photocatalytic process follow the pseudo-first-order kinetic model. Furthermore, TiO₂/AC retains high photocatalytic activity after five reaction cycles. This research provides valuable insights into the application of biomass-derived materials for the purification of water, offering a sustainable solution to both pollution and agricultural waste challenges in Plateau areas of China.

Perovskite solar cells (PSCs) represent one of the most promising emerging photovoltaic technologies due to their high power conversion efficiency. However, despite the huge progress made not only in terms of the efficiency achieved, but also fundamental understanding of the relevant physics of the devices and issues which affect their efficiency and stability, there are still unresolved problems and obstacles on the path toward commercialization of this promising technology. In this roadmap, we aim to provide a concise and up to date summary of outstanding issues and challenges, and the progress made toward addressing these issues. While the format of this article is not meant to be a comprehensive review of the topic, it provides a collection of the viewpoints of the experts in the field, which covers a broad range of topics related to PSC commercialization, including those relevant for manufacturing (scaling up, different types of devices), operation and stability (various factors), and environmental issues (in particular the use of lead). We hope that the article will provide a useful resource for researchers in the field and that it will facilitate discussions and move forward toward addressing the outstanding challenges in this fast-developing field.

Continual development of more advanced catalysts to support the more efficient electrocatalytic nitrogen reduction reaction (NRR) as a qualified substitute of the industrial Haber–Bosch reaction holds great significance but still remains largely underexplored. Many recent works have focused on research on the active central atom of single-atom catalysts (SACs) for electrochemical NRR; yet, a comprehensive investigation on the coordinating environment of the central atom of SACs to enhance the performance of electrochemical NRR has seldom been done and is thus imperative to be developed. Herein, from a DFT perspective, we propose a systematic research on modifiying the coordinating environment of Mn-SACs via diversification of two-dimensional (2D) monolayer supports, usage of the unsaturated form of N-doping, introduction of extra heteroatoms (F, P, and S), and external strain engineering to tune the performance of the electrocatalytic NRR. According to our thermodynamics, kinetics, and selectivity analysis, the N-doped graphene used as the support to anchor Mn-SAC ([email protected]₄) exhibits excellent behavior for electrocatalytic NRR. In addition, usage of the unsaturated form of N-doping, [email protected]₃C₁ and [email protected]₁C₃ in particular, can help improve the catalytic performance. Furthermore, introduction of extra O-heteroatoms to form a dual-heteroatom coordination structure ([email protected]₃C₁O₁) would significantly decrease the free energy requirement of fixation and activation of N₂ (ΔGN₂ = −0.61 eV; ΔG_NNH = 0.29 eV), thereby facilitating the electrocatalytic NRR efficiently. Finally, an appropriate external compressive strain engineering can be accepted as the effective strategy to enhance the electrocatalytic performance of NRR. All of the improvement of the NRR performance is mainly due to the energy decrease of the d-band center of the central atom of Mn-SCAs. Importantly, our efforts toward understanding the influence of the coordinating environment of the central atom of SACs on electrochemical NRR and strengthening the performance via decreasing the energy of the d-band center of the central atom would provide guidelines for further research including theory and experiment.