To enhance the economy and society's sustainability, prioritizing innovative, green energy conversion methods is essential. The conversion of solar energy into chemical energy through photocatalysis represents a viable solution in the pursuit of sustainable energy resources despite low solar-to-energy conversion efficiency. In recent years, the immobilization of metal active centers in nanospace has been considered an important strategy to improve photocatalytic performance. Metal–organic frameworks (MOFs), covalent organic frameworks (COFs) and hydrogen-bonded organic frameworks (HOFs), as exciting reticular framework materials, have attracted much attention due to their advantages of large specific surface area, high porosity and tunable functionalization sites, which are considered promising carriers for immobilizing metal sites. This paper introduces the structural features and advantages of each framework in photocatalysis, highlighting their potential applications in water splitting (H₂ or O₂ evolution) and CO₂ reduction. The review underscores the outstanding performance of metal-active sites within these frameworks. Finally, the current limitations and challenges of the reticular framework materials in photocatalysis are pointed out, and an outlook for future development is provided, which aims to inspire continued advancements in green energy solutions for a sustainable future.

This review highlights emerging electrothermal strategies, including Joule, microwave, plasma, induction, and laser heating, for selectively upcycling plastic waste into hydrogen, olefins, aromatics, and carbon materials under renewable energy input.

This study aims to evaluate the emissions of greenhouse gases (GHGs) stemming from the sludge treatment sector in China and to investigate the feasibility of novel technologies in curtailing these emissions, with the aim of fostering sustainable sludge management methodologies. Employing a life-cycle assessment (LCA) methodology, the research computed the comprehensive GHG emissions resulting from sludge treatment, taking into consideration diverse elements such as treatment techniques (e.g., landfills, incineration, and land application) and the geographical variations among China’s 660 municipalities. Findings indicate that the total amount of GHG emissions from sludge treatment amounted to 18.54 Mt CO₂-eq in 2017, with incineration registering the highest emissions (10,011.53 kg CO₂-eq/t dry sludge (DS)), followed by landfills (717.51 kg CO₂-eq/t DS) and land application (276.41 kg CO₂-eq/t DS). The geographical dispersion of emissions characteristics reveal notable regional disparities, with the top 1% of cities responsible for 34.2% of the overall emissions. The concentration of emissions in the top 1 percent of cities underscores the necessity for tailored mitigation measures that consider localized sustainable development challenges. Principal component analysis (PCA) demonstrates that economic determinants and treatment scales exert substantial influence on emissions, underscoring the imperative of aligning Sustainable Development Goals (SDGs) with economic advancement. To curtail the carbon footprint associated with sludge treatment and enhance sustainability, the study evaluated the emission mitigation potential and expenses of diverse technologies, encompassing thermal conversion, anaerobic digestion, hydrothermal treatment, and wet oxidation. These technologies have the capacity to slash GHG emissions by 0.09–0.46 t CO₂-eq/t DS in comparison to traditional approaches, while concurrently advancing resource recuperation and principles of circular economy. For instance, gasification could diminish GHG emissions by 0.33–0.46 t CO₂-eq/t DS, whereas anaerobic digestion could yield reductions of 0.09–0.30 t CO₂-eq/t DS. The implementation of these innovative technologies across 660 Chinese municipalities could potentially curtail total GHG emissions from sludge treatment by 15–40%. Nevertheless, further enhancements are imperative to refine their environmental and economic efficiency and guarantee enduring sustainability. By deploying these technologies and embracing optimization tactics, China’s sludge treatment sector can make a substantial contribution towards attaining national carbon neutrality objectives and advancing sustainable development.