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Interfacial solar‐driven water evaporation has shown promising prospects in desalination technology. However, the lower photothermal conversion efficiency caused by the intermittent nature of sunlight and salt accumulation remains a significant challenge for continuous desalination. Herein, the hierarchical design of interfacial solar evaporation is reported, which realizes enhanced photothermal conversion, waste heat storage/release, and effective thermal management for continuous desalination. The solar evaporator is composed of worm‐like SrCoO3 perovskite oxide anchored on super hydrophilic polyurethane (PU) foam succeeded by in situ polymerization of conducting polypyrrole (SrCoO3@PPy). The energy storage system is introduced within polyurethane matrix by a paraffin block followed by a tongue‐and‐groove structure for convective water transportation, and a heat recovery unit largely reduces heat losses. The solar evaporator possesses excellent evaporation rates (2.13 kg m−2 h−1) along with 93% solar‐to‐vapor conversion efficiency under 1 kw m−2 solar irradiation owing to its minimum equivalent evaporation enthalpy and (0.85 kg m−2 h−1) under intermittent solar irradiation as compared to conventional solar evaporators. More importantly, state‐of‐the‐art experimental investigations validate waste heat recovery/release and the salt‐resistant capability of solar evaporators optimized by computational fluid dynamic simulation. This study breaks conventional solar interfacial evaporation's limitations and demonstrates stable desalination under intermittent sunlight.

Quantum dots (QDs) with ultrahigh surface‐to‐volume ratio, abundant edge active sites, forceful quantum confinement and other remarkable physio‐chemical properties, have garnered considerable research interest. MXene QDs, as an emerging member of them, have also attracted wide attention in the last six years, and shown great achievements in many fields. This critical review systematically summarizes the various methods for synthesizing MXene QDs. The characteristics and corresponding applications of various MXene QDs are also presented. The advantages and disadvantages of various synthetic methods, and the limitations of corresponding MXene QDs are compared and highlighted. Finally, the challenges and perspectives of synthesizing MXene QDs are proposed. We hope this review will enlighten researchers to the fabrication of more advancing and promising MXene‐based QDs with proprietary properties in diverse applications.

Solar evaporation is a facile and promising technology to efficiently utilize renewable energy for freshwater production and seawater desalination. Here, the fabrication of self‐regenerating hydrogel composed of 2D‐MXenes nanosheets embedded in perovskite La 0.6Sr 0.4Co 0.2Fe 0.8O3−δ (LSCF)/polyvinyl alcohol hydrogels for efficient solar‐driven evaporation and seawater desalination is reported. The mixed dimensional LSCF/Ti3C2 composite features a localized surface plasmonic resonance effect in the polymeric network of polyvinyl alcohol endows excellent evaporation rates (1.98 kg m−2 h−1) under 1 k Wm−2 or one sun solar irradiation ascribed by hydrophilicity and broadband solar absorption (96%). Furthermore, the long‐term performance reveals smooth mass change (13.33 kg m−2) during 8 h under one sun. The composite hydrogel prompts the dilution of concentrated brines and redissolves it back to water (1.2 g NaCl/270 min) without impeding the evaporation rate without any salt‐accumulation. The present research offers a substantial opportunity for solar‐driven evaporation without any salt accumulation in real‐life applications.

There is tremendous potential for both small- and large-scale applications of low-temperature operational ceramic fuel cells (LT-CFCs), which operate between 350 °C and 550 °C. Unfortunately, the low operating temperature of CFCs was hampered by inadequate oxygen reduction electrocatalysts. In this work, the electrochemical characteristics of a semiconductor heterostructure composite based on WO3-CaFe2O4 deposited over porous Ni-foam are investigated. At low working temperatures of 450–500 °C, the developed WO3-CaFe2O4 pasted on porous Ni–foam heterostructure composite cathode exhibits very low area-specific resistance (0.78 Ω cm2) and high oxygen reduction reaction (ORR) activity. For button-sized SOFCs with H2 and atmospheric air fuels, we have demonstrated high-power densities of 508 mW cm−2 running at 550 °C, and even potential operation at 450 °C, using WO3-CaFe2O4 seeded on porous Ni-foam cathode. Moreover, WO3-CaFe2O4 composite heterostructure with Ni foam paste exhibits very low activation energy compared to both WO3 and CaFe2O4 alone, which supports ORR activity. To comprehend the enhanced ORR electrocatalytic activity of WO3-CaFe2O4 pasted on porous Ni-foam heterostructure composite, several spectroscopic tests including X-ray diffraction (XRD), photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS) were used. The findings may also aid in the creation of useful cobalt-free electrocatalysts for LT-SOFCs.