Phase change materials (PCMs) possess considerable promise for harnessing and storing solar energy. However, the widespread application of conventional solid-liquid PCMs in solar technologies is hindered by inherent limitations, such as phase segregation, leakage and low photothermal conversion efficiency. To overcome these limitations, a novel composite material comprising solid-solid phase change material and high-entropy nano-carbon (SSPCM-H) has been developed. This material employs polyethylene glycol (PEG) to construct a cross-linked polymer for latent heat storage, whilst incorporating high-entropy nanocarbon (HENC) as the photo-thermal nanomaterials. The cross-linked 3D network enhances the intermolecular forces, thereby granting the material exceptional structural stability. The optimal SSPCM-H 0.2% composite demonstrated a high photo-thermal conversion efficiency of 89.7%, combined with a fusion enthalpy of 149.5 J/g. This highlights the potential for developing more efficient and adaptable clean energy solutions in thermal energy storage and thermoelectric conversion.

Sodium sulfate decahydrate (Na2SO4·10H2O, SSD) is a promising hydrated-salt phase change material for low- and medium-temperature thermal management. However, severe supercooling, leakage after melting, and inefficient solar utilization limit its application. Herein, we construct a hydrophilic three-dimensional AM/CMC-Na network and introduce borax as a nucleating agent and trace high-entropy-alloy (HEA) particles as photothermal and thermally conductive fillers. The network confines SSD and suppresses leakage after heating at 50 °C for 1 h. With 0.4% borax relative to SSD, the supercooling degree decreases to 1.48 °C; with 50 ppm HEA, it further decreases to 1.31 °C, while the melting and crystallization enthalpies remain 129.0 and 127.8 J g−1, respectively. Increasing HEA content strengthens optical absorption and heat transport, increasing photothermal conversion efficiency from 65.6% to 87.5% and thermal conductivity from 0.605 to 1.354 W (m K)−1. The hydrogel withstands 2.2 MPa compressive stress at 50% strain and retains thermal reliability with about 8% enthalpy loss after 100 heating-cooling cycles. After cold storage at 20 °C, it keeps the temperature below 36 °C for about 4.7 h in a 40 °C environment; during contact thermal management, it provides about 1.2 h of heat absorption and a heat-release plateau at 28 °C for about 1 h. These results show that ppm-level HEA effectively improves the photothermal response and bidirectional thermal management capability of SSD-based phase change hydrogels.

The growing global challenge of freshwater scarcity necessitates the advancement of efficient solar-driven atmospheric water harvesting (AWH) technologies. This study addresses critical limitations in conventional salt-based sorbents, such as salt leakage and high energy requirements for water desorption, by developing a novel photothermal-enhanced composite hydrogel (ADPP-Li). The material is engineered through the integration of polydopamine-which chelates Li+ ions to prevent leakage-and polypyrrole as a highly efficient solar absorber within a stable polyacrylamide-based 3D interpenetrating network. The results show that the composite hydrogel exhibits excellent moisture adsorption capacity (4.1 g/g at 90% RH and 25 °C), efficient photothermal conversion with rapid desorption (releasing 89.5% of adsorbed water within 70 min under 1.0 sun irradiance), and stable cyclic performance (retaining 92% of its capacity after 60 cycles). In real outdoor tests, the material can harvest 1.76 L/kg of water per day. Notably, the hydrogel also displays synergistic moisture-induced electricity generation characteristics, delivering an output voltage of 630 mV at 67% relative humidity. Even under fluctuating humidity and varying light intensities, the ADPP-Li hydrogel maintains stable water collection and energy output, highlighting its practical feasibility for real-world freshwater and energy supply.

Advanced oxidation processes utilizing peracetic acid (PAA) have garnered significant interest for the removal of micropollutants, while the mechanisms of employing both the light and thermal energy of solar radiation to activate PAA have not been explored. This study adopted the reduced graphene oxide (rGO) as a photothermal material under solar radiation to synergistically activate PAA for the degradation of carbamazepine (CBZ). The temperature notably increased to a maximum of 63.0 degrees C under the rGO concentration of 5 mg/L, and an optimal removal efficiency of 92.45 % with a kobs of 0.014 min(-1) was achieved. The primary mechanism for CBZ removal was the generation of reactive species through the photoactivation and thermal activation of PAA under solar irradiation. Radical quenching experiments and electron spin resonance analysis identified CH3C(O)OO center dot as the principal contributor to CBZ degradation. Seven potential transformation products of CBZ were identified, and three possible degradation pathways were proposed. The toxicity of CBZ polluted water was effectively reduced after photothermal-activated PAA treatment. The removal efficiency of CBZ remained above 90 % after four consecutive cycles of rGO reuse. This study comprehensively elucidates the mechanism of photothermal activation of PAA and thus contributes to the degradation of micropollutants.

Solar-driven interfacial evaporation technology has been regarded as one of potential sustainable solutions to the global freshwater shortage crisis due to its high efficiency, low energy consumption, and environmental friendliness. However, it remains a key challenge to develop an efficient and stable interface evaporator. In this study, we designed a self-floating solar-driven interface evaporator by fabricating wood-like structure biomass aerogels together with bamboo fabric and polystyrene foam for high-efficiency desalination and purification. By introducing 3-glycidyloxypropyltrimethoxysilane (GPTMS) as a multifunctional crosslinking agent, an innovative synergistic preparation strategy was proposed by combining one-pot polycondensation with ice-templateinduced growth. This approach successfully constructed a three-dimensional (3D) vertically oriented porous cellulose nanofiber/polyvinyl alcohol/multi-walled carbon nanotube composite biomass aerogel. Within the system, GPTMS significantly enhances the 3D network stability of the aerogel while synergistically regulating the hydrophilicity of its pores, thereby optimizing water transport and evaporative interface stability. The vertical porous wood-like architecture enabled efficient water transport and light harvesting. Under simulated solar illumination (1 kW & sdot;m-2) and simulated 3.5 wt% salinity, the aerogel evaporator achieved an evaporation rate of 1.78 kg & sdot;m-2 & sdot;h-1 , and an evaporation efficiency of 90.43 %. After 12 operating cycles in real seawater, the mean evaporation rate was 1.51 kg & sdot;m-2 & sdot;h-1 , with a maximum value of 1.63 kg & sdot;m-2 & sdot;h-1 . During outdoor testing, the aerogel evaporator achieved an evaporation rate of 0.96 kg & sdot;m-2 & sdot;h-1 . Additionally, the evaporators effectively removed organic contaminants and heavy-metal ions, achieving up to 98 % removal efficiency in heavy metal condensate. This study provides references for developing high-performance biomass-basedsolar interfacial evaporators.

This acid-etched iron foam and ionic hydrogel MEG outputs 0.58 V, works 7+ days at 30–90% RH, and powers LEDs and wearables.

The intermittency and instability of solar energy lead to temporal and spatial mismatches between supply and demand, thereby restricting its utilization efficiency. Phase change materials (PCMs) are promising candidates for solar heat storage; however, their spontaneous crystallization during heat release limits the duration of latent heat storage. Herein, we developed composite PCMs with pronounced supercooling to overcome these limitations. Sodium acetate (SA)-water was first employed as the phase change matrix, with hydroxyethyl cellulose (HEC) enhancing supercooling stability and carbon microspheres (CB) improving photothermal conversion efficiency. The optimized SA/HEC-CB80 composite exhibited a high photothermal efficiency of 96.43 %, retained stability for over 120 days even at-18 degrees C to-20 degrees C, and enabled controlled latent heat release through electrical triggering. In practical demonstrations, the system realized "summer storage and winter use," delivering a continuous supply of 40 degrees C hot water for 3.5 h, while an integrated emergency garment achieved a temperature increase of 5-8 degrees C within 60 s through mechanical triggering. This study offers a feasible strategy for efficient cross-seasonal solar thermal storage, effectively mitigating the temporal-spatial mismatch in solar energy utilization.

In thermal management, traditional composite phase change materials (CPCMs) face leakage and flexibility issues, affecting their performance in human temperature regulation and electronic device cooling. This study proposes an innovative phase change hydrogel synthesized by the sol-gel method using acrylamide (AAM), hydroxyethyl cellulose (HEC), sodium acetate trihydrate (SAT), and graphene oxide (GO). The unique combination of these components endows the hydrogel with leakage prevention, flexibility, and enhanced photothermal conversion efficiency, thus improving its thermal management capabilities for both human and electronic devices. Additionally, the graphene oxide-incorporated composite exhibits an exceptional photothermal conversion efficiency of 91.4% under 1 sun irradiation, facilitating solar-powered thermotherapy in wearable devices, while its thermal conductivity achieves a 150% enhancement over pure SAT, significantly improving heat dissipation in electronics. In practical application of human joint thermotherapy, it closely adheres to the joint area and provides a temperature environment of 38-45 degrees C for 20min when the environmental temperature changes, effectively alleviating joint discomfort. In terms of LED lamp heat dissipation, thermal interface material (TIM) reduces the surface temperature of the electronic device by 9-16 degrees C, showing the potential to prolong the service life of the lamp. This study provides a solid foundation for advancing CPCM technology in addressing the thermal management of human body and electronic devices.

Solar evaporation exhibits significant potential for the treatment of high-salt organic wastewater. However, it's also confronted with challenges due to the accumulation of organic pollutants and salts in the concentrated wastewater following evaporation, which compromises the long-term stability of evaporation unit and complicates subsequent treatment processes. To address these challenges, a volumetric solar interfacial evaporation (V-SIE) system by integrating Fe3O4 -H2O nanofluids and peroxydisulfate (PDS) were proposed in this study. In V-SIE system, Fe3O4 magnetic nanoparticles (NPs) were prepared as solar receivers to form a volume-absorbing solar energy interface and enhance evaporation efficiency. The results show that the evaporation rate was 1.412 kg/(m2·h) and the solar efficiency reached 93.75 % as the temperature rose to 57.2 ℃. Additionally, the high thermal conductivity of Fe3O4 facilitated the effective heat transfer to the fluid and provided sufficient thermal energy to activate PDS, thereby removing 99.3 % of Rhodamine B (RhB). Fe3O4 NPs effectively promoted the generation of reactive species including SO4 ·-, ·OH, O2 ·- and 1O2 from PDS and the four main stages including N-de-ethylation, chromophore cleavage, ring-opening, and mineralization were proposed as the possible degradation pathway of RhB. This study provides a reference for developing V-SIE system and highlights the positive effect of nanofluids in advanced oxidation processes.

Transeasonal heat storage in organic phase change materials (PCMs) present a promising solution to the intermittent nature of renewable energy. However, PCMs are prone to spontaneous crystallization during storage, leading to the loss of stored latent heat in low-temperature environments. In this study, we incorporated tetrasodium ethylenediaminetetraacetic acid (EDTA-4Na) and superabsorbent polymer (SAP) to erythritol (ERY), referred to as EES-PCMs, to overcome these challenges and achieve more controllable and stable thermal energy storage. The incorporation of EDTA-4Na and SAP into ERY significantly improves the supercooling stability and phase change enthalpy. The optimal ratio (EES-PCMs-2) of phase change enthalpy reaches an impressive 286.62 J/g, with stable performance maintained for 120 days at room temperature. The EES-PCMs-2 exhibits exceptional thermal cycling stability, retaining its properties even after 100 cycles. A novel air-triggered crystallization method is demonstrated, enabling a temperature increase from room temperature to 48.21 C-degrees in 320 s after being exposed to air for long-term storage. This innovative approach effectively overcomes the limitations of traditional triggering mechanisms, providing a straightforward and efficient method for thermal management. The high thermal storage capacity, stability, and controlled exothermic properties of EES-PCMs position them as promising candidates for applications in seasonal solar thermal energy storage.

To achieve sustainable adsorbent regeneration in wastewater treatment, a novel in-situ regeneration strategy using photothermally activated peroxydisulfate (PDS) oxidation was developed. Here, magnetic cobalt nanoparticles embedded in nanoporous carbon (Co@NC) were synthesised at different carbonization temperatures, and their potential for removing fulvic acid (FA) were assessed during adsorption-regeneration cycles. The results revealed that Co@NC prepared at 700 degrees C (Co@NC@700) exhibited excellent adsorption and regeneration capabilities, as well as outstanding photothermal properties. The FA removal rate could reach 90% during the adsorption process, and Co@NC@700 could be efficiently separated from water by magnetic force. Under irradiation equivalent to four suns, the Co@NC@700 system reached 70 degrees C with a photothermal conversion efficiency of 65%, providing ample thermal energy for PDS activation. Even after seven photothermal regeneration cycles, over 55% of the original adsorption capacity could still be recovered. Compared with direct desorption without degradation, the total organic carbon (TOC) content in the regeneration solution reduced to 18.84 mg/L, achieving a removal rate of 83%. The quenching experiments, electron paramagnetic resonance and electrochemistry tests indicated that both radical and non-radical pathways contributed to the regeneration process. By harnessing renewable solar energy, this study provides a feasible approach for simultaneous in-situ adsorbent regeneration and containment removal.

Solar evaporation is a promising method for water purification, but it often faces challenges such as scale formation of organics after feed water evaporation and low efficiency in evaporation. In response, we created a dual-function system based on the photothermal active peroxydisulfate (PDS) technique. The system serves both double-sided evaporation to improve evaporation efficiency and simultaneous removal of organic contaminant scale accumulation. Wastewater containing PDS is extracted by capillary force through a photothermal fabric, evaporating on both surfaces under sunlight. Concurrently, the thermal energy generated during the steam generation process can break the O-O bond of PDS, generating sulfate radicals (SO 4 & sdot;- ) that decompose organic pollutants. The design achieves a rapid evaporation rate of 5.47 kg m- 2 h-1 and a high solar efficiency of 89.9 % under sunlight irradiation (4000 W/m 2 ). Additionally, it demonstrates a 99.8 % RhB removal efficiency in concentrated brine. Importantly, highly concentrated brine can be collected without solid-salt accumulation. This development enhances the potential of solar distillation for wastewater treatment.

Tetracycline(TC)as a typical emerging pollutant is becoming a serious threat to the environment and hu-man health.A combined advanced oxidation technology of UV/Ozone(O3)/peroxydisulfate(PDS)process was developed to explore an efficient and economic treatment process of TC in wastewater.Furthermore,the reactive sites and transformation pathways of TC were explored and the toxicity of the intermedi-ates was quantified with a quantitative structure-activity relationship(QSAR)assessment.The degrada-tion performance of TC was substantially enhanced in UV/O3/PDS process with a kobs of 0.0949 min-1,which was 2.3 times higher than UV/O3 and 3.2 times than sole UV.The results demonstrated that there was a superior synergistic effect of PDS on UV/O3 processes for the degradation of TC.Electron para-magnetic resonance(EPR)analysis and quenching experiments show that·OH,SO4·-,O2·-and 1O2 all contributed to TC degradation in the UV/O3/PDS process and exhibited a synergistic effect,which inhib-ited the generation of harmful products.In addition,the UV/O3/PDS system can effectively degrade TC in a wide range of substrate concentrations and pH,and also showed excellent adaptability to various con-centrations of anions(Cl-and HCO3-).This study proves the feasibility of UV/O3/PDS process for treating TC contaminated wastewater with complicated water matrix.

Efficient removal of contaminants from landfill leachate remains to be a major challenge, calling for novel technologies for advanced treatment of those high-salinity wastewaters. In this work, an iridium-decorated electrochemical ceramic membrane was fabricated via magnetron sputtering deposition for the treatment of landfill leachate. The electrochemical ceramic membrane filtration (ECMF) system achieved 70.8 +/- 1.5 % of chemical oxygen demand (COD) and 31.7 +/- 2.8 % of total nitrogen under hydraulic retention time (HRT) 60 min and membrane flux 50 L/(m(2) h) during 14-d operation. Furthermore, the ratio of biochemical oxygen demand (BOD) to COD in the effluent was increased to 0.56 in comparison to that of the influent (0.24), indicating the increase in the biodegradability of the effluent. The reactive chlorine species generated in the system were mainly responsible for the pollutant removal in this system, efficiently oxidizing the humic substances and reducing the aromaticity of the contaminants. The energy consumption and current efficiency of the ECMF system were 49.3 kWh/ kg COD and 37.4 % at 20 mA cm(-2), respectively. The results of this study highlight the potential of using the ECMF system for efficient treatment of high-salinity wastewater.

Exploring low-cost, high-efficiency photothermal materials has an important significance in solar thermal utilization. In this work, a sewage sludge-derived biochar (SDBC) as an efficient solar receiver is fabricated via a simple pyrolysis method and applied in peroxydisulfate (PDS) activation based on the fact that PDS can be thermally activated. Under the irradiation of concentrated solar light, the SDBC exhibits excellent broadspectrum response and high photothermal conversion performance. The heat generated from light conversion provides sufficient activation energy for activating PDS. Meanwhile, PDS can also be directly activated by ultraviolet rays in the solar spectrum. Combining with oxidation species analysis, the underlying mechanism of photothermal-activation PDS is developed. As a proof of concept, an example of treating landfill leachate is taken. The present results demonstrate great potential for degrading landfill leachate in the actual water, which provides a new perspective on the utilization of solar energy for wastewater treatment.

Peroxydisulfate (PDS)-based advanced oxidation processes (AOPs) have been demonstrated to be an effective technology for the removal of refractory organic contaminants from the aquatic environment. Herein, a photothermal synergistic strategy is developed to realize the green activation of PDS under solar light irradiation. An innovative solar photothermal reaction system and its corresponding evaluation method are established. The results show that there is a synergistic effect between light and light-generated thermal effects on the activation of PDS for effectively removing fulvic acid (FA). The maximum degradation percentage of FA increases from 42.6% to 90.8% after introducing ZrC nanoparticles as photothermal materials. The maximum temperature of the whole system is up to 66.4 ℃ after 120 min irradiation at 0.007 wt% solid content of ZrC, which is higher by 26.9% compared with that in the absence of ZrC nanoparticles. Furthermore, the underlying mechanism and PDS activation efficiency are deeply investigated. This work provides a viable strategy for directly using solar radiation to activate PDS for degrading refractory organic compounds, which creates a new avenue toward the utilization of solar energy for wastewater treatment.

基于上海城镇污水处理厂AAO-MBR膜工艺长期运行中膜不可逆污染严重、离线化学清洗难以恢复理想通量的问题,对其清洗方式进行改进.在原清洗方式的基础上增加草酸二次清洗,探究污染膜产水能力恢复情况,并通过中试试验进行验证.结果表明:膜清洗方式改进后,离线清洗对膜污染物的去除更加彻底,清水通量可恢复至新膜的95.1％,较原清洗方式提高了27.2％.在相同通量下中试运行24 d后,膜运行压力比原清洗方式低18.2 kPa,膜污染速率明显减慢.研究通过改进MBR长期运行平板膜的污染物清洗方法,为今后MBR污水厂膜清洗提供参考,具有较好的工程指导意义.

Nanofluids based direct absorption solar collectors (DASCs) are considered as the important alternative for further improve the utilization of solar energy. However the low-quality energy and aggregation of nanoparticles obstructs their large-scale application. In this work, a new method of using magnetic nanofluids in DASCs is proposed. By this method, not only high-quality energy is got as well as the problems of blockage and corrosion in heat exchanger are well avoided. The result shows that the maximum temperature can reach 98 °C under 3 solar irradiations and the photothermal conversion efficiency can be further increased by 12.8% when the concentration is 500 ppm after adding an external rotating magnetic field. The highest viscosity of working fluid reduced by 21% when the concentration is 500 ppm at 95 °C after separating the Fe3O4@C nanoparticles from the nanofluids via magnetic separation technology. Meanwhile, the obtained pure base liquids with high temperature flow to heat exchanger, which also reduces the flow resistance in pipeline and avoids the problems such as blockage and corrosion in heat exchanger. This research promotes a new way for the efficient utilization of solar energy.

Efficiency is an important factor in the utilization of solar energy. Direct absorption solar energy collectors (DASCs), a new generation collector of converting solar irradiation into heat directly by nanofluids, is regarded as a promising solution for capturing solar energy with high efficiency. Both good stability and high absorption ability are crucial for nanofluids to be an ideal working fluid of DASCs. In this work, we synthesize hyperstable Ti3C2Tx-H2O nanofluids as the working fluids of DASCs and investigate its photothermal conversion performance. The results show that the maximum conversion efficiency of thin-layer Ti3C2Tx nanofluids achieves 91.9% at a very low mass fraction of 0.02 wt%, which is higher than that of multi-layer Ti3C2Tx samples. Based on the experimental results, a simulation model is built to observe the radiation energy transformation in DASCs and results show that better photothermal performance of thin-layer MXene Ti3C2Tx stems from its stronger localized surface plasmon resonance (LSPR) effect. Besides, the coupling effect and the shape of Ti3C2Tx particles also play important roles in photothermal absorption and conversion. Based on our experimental and numerical results, the Ti3C2Tx-H2O nanofluids have great potential in solar energy harvesting.

本文通过“两步法”制备了一种具有高光热转换效率的Fe3O4-H2O磁性纳米流体.该纳米流体可以通过磁分离技术实现纳米颗粒与基液的分离,使得纳米流体基液得以直接使用,同时具有优异的可重复利用性能.实验结果表明,在1200 s内其光热转化效率高达70.2％,并且经过60次的循环使用后无明显的衰减.此研究结果为实现纳米流体基液的直接应用提供了可行性的方案.