The immense progress of humanity on the technological, domestic, and industrial fronts comes at the cost of polluting the planet. Aquatic pollution is particularly dangerous since all life forms are directly linked to it. Each year tons of industrial and domestic pollutants make their way into aqueous systems. Efficient removal/degradation of these pollutants is of prime importance for the sustainable future. Among many technologies, photodegradation is an emerging and promising method for the successful removal of aqueous pollutants since it is powered by abundant solar light. The last decade had shown that carbon dots are among the most promising materials that can be utilized as an efficient tool to derive various solar‐driven chemical reactions. Carbon dots possess unique photophysical and chemical properties such as light‐harvesting over a broad‐spectrum region, upconversion photoluminescence, photosensitizers, chemical inertness, and bivalent redox character, etc. The ease of synthesis of carbon dots at low cost also contributes hugely to their utilizations as an efficient photocatalyst for the degradation of aqueous pollutants. This review summarizes the recent progress made in the field of photodegradation of aqueous pollutants with the aid of carbon dots and their hybrids, highlighting the critical role carbon dots can play in the field.

The growing global energy demand and worsening climate change highlight the urgent need for clean, efficient and sustainable energy solutions. Among emerging technologies, atomically thin two-dimensional (2D) materials offer unique advantages in photovoltaics due to their tunable optoelectronic properties, high surface area and efficient charge transport capabilities. This review explores recent progress in photovoltaics incorporating 2D materials, focusing on their application as hole and electron transport layers to optimize bandgap alignment, enhance carrier mobility and improve chemical stability. A comprehensive analysis is presented on perovskite solar cells utilizing 2D materials, with a particular focus on strategies to enhance crystallization, passivate defects and improve overall cell efficiency. Additionally, the application of 2D materials in organic solar cells is examined, particularly for reducing recombination losses and enhancing charge extraction through work function modification. Their impact on dye-sensitized solar cells, including catalytic activity and counter electrode performance, is also explored. Finally, the review outlines key challenges, material limitations and performance metrics, offering insight into the future development of next-generation photovoltaic devices encouraged by 2D materials.

The combination of the ability to absorb most of the solar radiation and simultaneously suppress infrared re-radiation allows selective solar absorbers (SSAs) to maximize solar energy to heat conversion, which is critical to several advanced applications. The intrinsic spectral selective materials are rare in nature and only a few demonstrated complete solar absorption. Typically, intrinsic materials exhibit high performances when integrated into complex multilayered solar absorber systems due to their limited spectral selectivity and solar absorption. In this study, we propose CoSb_x (2 < x < 3) as a new exceptionally efficient SSA. Here we demonstrate that the low bandgap nature of CoSb_x endows broadband solar absorption (0.96) over the solar spectral range and simultaneous low emissivity (0.18) in the mid-infrared region, resulting in a remarkable intrinsic spectral solar selectivity of 5.3. Under 1 sun illumination, the heat concentrates on the surface of the CoSb_x thin film, and an impressive temperature of 101.7 °C is reached, demonstrating the highest value among reported intrinsic SSAs. Furthermore, the CoSb_x was tested for solar water evaporation achieving an evaporation rate of 1.4 kg m⁻² h⁻¹. This study could expand the use of narrow bandgap semiconductors as efficient intrinsic SSAs with high surface temperatures in solar applications.

Solar water evaporation offers a promising solution to address global water scarcity, utilizing renewable energy for purification and desalination. Transition-metal selenite hydrates (specifically nickel and cobalt) have shown potential as solar absorbers with high evaporation rates of 1.83 and 2.34 kg∙m⁻²∙h⁻¹, but the reported discrepancy in evaporation rate deserves further investigation. This investigation aims to clarify their thermal stability for applications and determine the underlying mechanisms responsible for the differences. Nickel and cobalt selenite hydrate compositions were synthesized and investigated via thermogravimetric analysis, X-ray diffraction, and Raman spectroscopy to assess their temperature-induced structural and compositional variations. The results reveal distinct phase transitions and structural alterations under various temperature conditions for these two photothermal materials, providing valuable insights into the factors influencing water transportation and evaporation rates.

Environmental pollution is a complex problem that threatens the health and life of animal and plant ecosystems on the planet. In this respect, the scientific community faces increasingly challenging tasks in designing novel materials with beneficial properties to address this issue. This study describes a simple yet effective synthetic protocol to obtain nickel hexacyanoferrate (Ni‐HCF) nanocubes as a suitable photocatalyst, which can enable an efficient photodegradation of hazardous anthropogenic organic contaminants in water, such as antibiotics. Ni‐HCF nanocubes are fully characterized and their optical and electrochemical properties are investigated. Preliminary tests are also carried out to photocatalytically remove metronidazole (MDZ), an antibiotic that is difficult to degrade and has become a common contaminant as it is widely used to treat infections caused by anaerobic microorganisms. Under simulated solar light, Ni‐HCF displays substantial photocatalytic activity, degrading 94.3% of MDZ in 6 h. The remarkable performance of Ni‐HCF nanocubes is attributeto a higher ability to separate charge carriers and to a lower resistance toward charge transfer, as confirmed by the electrochemical characterization. These achievements highlight the possibility of combining the performance of earth‐abundant catalysts with a renewable energy source for environmental remediation, thus meeting the requirements for sustainable development.