Meng Lin

Transparent silica aerogels can reduce heat loss from solar receivers while maintaining high solar transmission, but their performance under fluctuating irradiation is governed by the coupled effects of solid conduction, non-gray thermal radiation, and time-dependent fluid heat extraction. Here, we develop and experimentally validate a transient 5-band model for an aerogel-covered solar receiver for fluid heating. The model resolves wavelength-dependent radiative transport within the aerogel and couples it with heat conduction and forced convection. We show that conduction and radiation cannot be reconstructed from isolated calculations because both adjust to a shared temperature field. The coupled heat flux at the aerogel-absorber interface is 23-31% lower than the directly superposed value, while appearing accurate at the external aerogel surface because the internal coupling effects compensate spatially. Flow regulation introduces a further trade-off between outlet temperature rise and response speed. Simulations driven by measured global horizontal irradiance in Shenzhen show that the flow adjustment interval mainly controls short-term temperature stability, whereas the irradiation regime and periods of flow interruption dominate the integrated thermal performance. These results establish a transport-based framework for understanding and regulating transparent aerogel covered solar receivers under variable solar input.

Solar energy utilisation is pivotal for advancing sustainable and renewable energy solutions, yet the rational design of high‐efficiency photothermal conversion devices remains a critical challenge. This paper systematically examines the evolution of photothermal reactor architectures from two‐dimensional (2D) to 3D structures, emphasising their respective roles in overcoming performance limitations. We highlight the superior spectral selectivity and enhanced high‐intensity irradiation absorption of 2D materials, alongside the advantages of 3D configurations in optimising temperature distribution and energy transfer efficiency. Two fundamental design strategies are critically evaluated: enhancement of intrinsic photothermal material properties and engineering of optical structures for improved light management. Key material considerations, including fabrication techniques, incidence angle dependence, light absorption bandwidth and application‐specific performance, are comprehensively discussed. Our analysis reveals that advanced 2D photothermal reactor design increasingly relies on extending optical path lengths and transcending inherent material constraints, accompanied by growing complexity in optical effect integration. This review provides a roadmap for the synergistic design of 2D and 3D photothermal reactors, aiming to accelerate their commercial viability and contribute to the next generation of solar energy utilisation technologies.

Conventional carbon dioxide (CO ₂ ) capture systems are constrained by limited uptake capacity and energy-intensive regeneration. Here, we formulate a microporous carbon capture solution (MCCS) by dispersing a permanent-porosity framework (ZIF-67) in a liquid absorbent, coupling solvent-excluded physisorption with chemical uptake and boosting the CO ₂ capture capacity by ∼45%. Instead of bulk thermal stripping, we implement interfacial, microbubble-activated regeneration (MAR) with a decreased monoethanolamine (MEA) loss rate by ∼38%. Microbubble activation refreshes gas-liquid-solid contact to liberate 100% physiosorbed CO ₂ , whereas microbubble-collapse events that mechanically trigger contact electrocatalysis (CEC), enabling interfacial hydroxyl radicals (•OH) that cleave carbamates under mild conditions and regenerates a substantial additional 37 to 55% of chemically absorbed CO ₂ . Theoretical analyses reveal that •OH is the key species governing CO ₂ regeneration in the CEC-MAR process through oxidative carbon-nitrogen bond cleavage, followed by •H-assisted intermediate reduction to regenerate the amine. To approach engineering relevance, we realize kilogram-scale zeolitic imidazolate framework (ZIF) synthesis under ambient conditions using simple mechanical stirring, providing scalable MCCS inventory to enable (i) continuous delivery of high-purity CO ₂ (1437 millimoles over 200 minutes) from a laboratory-scale integrated system and (ii) direct electroreduction to carbon monoxide (CO) with a faradaic efficiency (FE _CO ) of 51% without CO ₂ supply. More broadly, it establishes a porous-liquid, interfacial-regeneration paradigm that decouples capacity from stoichiometry and enables electrified, continuous CO ₂ capture, regeneration, and utilization under scalable, low-temperature conditions.

Air-to-methane pathways typically treat direct air capture (DAC) and water electrolysis as independent units for separate CO2 and H2 supply, leading to large energy and cost penalties. We introduce an integrated air methanation (IAM) concept that cascades electrochemical DAC into direct air electrolysis (DAE): by feeding the CO2-free, humid DAC effluent directly to the electrolyzer, the system enables alkaline DAE without air-CO2-induced carbonation that would otherwise occur in an air-fed electrolyzer. Furthermore, DAE-generated H2 acts as a sweep gas to lower CO2 partial pressure and increase DAC charge utilization. Our techno-economic analysis shows that this integration decreases the minimum specific energy from 2376.8 to 1078.3 kJ/mol CH4 (−54.6%) compared to a decoupled configuration. The analysis further predicts a cost reduction from $3566.7 to $2715.0/ton CH4 (−23.9%) and identifies electricity price, polarization losses, and stack capital cost as the dominant levers toward $1091.2/ton CH4.

This study develops a full-chain ship-to-port decarbonization framework integrating onboard carbon capture, port-side green hydrogen production, and downstream fuel synthesis, using Ningbo-Zhoushan Port as the case study. For five representative vessel types, onboard TSA-based CCS units are designed under the EEDI Phase III requirement and further coupled with CO2-H2 methane and methanol synthesis pathways for comparative evaluation, with thermodynamic, economic, and environmental analyses. The results show that the onboard TSA-based CCS unit exhibits favorable shipboard adaptability and economic feasibility under the Net-Zero strategy. Taking the Capesize vessel as the reference case, the system captures 1,593.18 kg/h CO2 at 75% engine load, reducing GFIattained from 76.36 to 59.29 gCO2eq/MJ. Meanwhile, CO2 capture rate, adsorption efficiency, specific heat consumption, and liquefaction exergy efficiency are 99.83%, 8.23 kg/tCO2·h, 4.07 GJ/tCO2, and 40.26%, while payback period is 0.90 year. Moreover, the ULCV shows the shortest payback period of 0.84 year, whereas the Capesize achieves the highest annual captured CO2 amount of 9,651.48 t and can continuously generate surplus units until 2033. For downstream utilization, the methanation unit achieves the CH4 purity of 98.17%, with energy and exergy efficiency of 64.14% and 42.37%, respectively, while the payback period is 7.51 years. By contrast, the methanol synthesis unit produces 99.99% CH3OH, with energy efficiency of 57.56%, exergy efficiency of 87.23%, payback period of 5.37 years. The comparative assessment indicates that methanation is more suitable for CO2 utilization based on existing natural-gas infrastructure, whereas methanol synthesis shows stronger overall competitiveness in the present port scenario.

This study develops a full-chain ship-to-port decarbonization framework integrating onboard TSA carbon capture, port-side green hydrogen production, and downstream fuel synthesis, using Ningbo-Zhoushan Port as the case study. For five representative vessel types, onboard TSA-based CCS units are designed under the EEDI Phase III requirement and further coupled with CO2-H2 methanation and methanol synthesis. The results show that the onboard TSA-based CCS unit exhibits favorable shipboard adaptability and economic feasibility under the Net-Zero strategy. Taking the Capesize vessel as the reference case, the system captures 1,593.18 kg/h CO2 at 75% engine load, reducing GFIattained from 76.36 to 59.29 gCO2eq/MJ. Meanwhile, α, β, SHC, and ηex,liq reach 99.83%, 8.23%, 4.07 GJ/tCO2, and 40.26%, while PBPOCCS is 0.90 year. Moreover, the ULCV shows the shortest PBPOCCS of 0.84 year, whereas the Capesize achieves the highest annual captured CO2 amount of 9,651.48 t and can continuously generate surplus units until 2033. For downstream utilization, the methanation unit achieves the CH4 purity of 98.17%, with ηen,MET and ηex,MET of 64.14% and 42.37%, respectively. By contrast, the methanol synthesis unit produces 99.99% CH3OH, with ηen,MEO is 57.56%, ηex,MEO is 87.23%, PBPMEO is 5.37 years. In summary, methanation is more suitable for CO2 utilization based on existing natural-gas infrastructure, whereas methanol synthesis shows stronger overall competitiveness in the present port scenario.

Gigaton‐scale carbon removal demands geologic permanence at low land, water, and energy cost. Ocean pathways are promising, but many electrochemical routes require large pH swings, membranes/sorbents, and suffer from fouling. We report the self‐biased electro‐mineralization as a practical route to ocean carbon removal. Porous core‐shell electrodes program interfacial fields that direct Ca ²⁺ /CO ₃ ²⁻ transport and trigger in‐pore crystallization in simulated seawater, without membrane stacks or large bulk pH swings. Field strength is tunable via core/shell ratio, polymer chemistry, and fixed‐charge density, enabling the architecture to deliver long‐duration, fouling‐resistant operation (>2000 h), ∼25% DIC conversion under flow. A 400 cm ² cell and a simple 100‐liter stirred reactor show that the microscale, uniform field both preserves performance under geometry area scale‐up and enables low‐overhead capacity expansion. Techno‐economic analysis projects an energy consumption of 44 kJ mol ⁻¹ CO ₂ and a cost of $139 t ⁻¹ CO ₂ . Extending beyond CaCO ₃ , we precipitate additional sparingly soluble phases (CaF ₂ , BaSO ₄ , PbSO ₄ ) from complex brines, establishing a platform also supporting resource recovery. These results shift ocean mineralization from bulk‐solution manipulation to programmable reaction‐environment design, advancing a scalable, cost‐effective pathway to climate relevant carbon removal.

Gigaton‐scale carbon removal demands geologic permanence at low land, water, and energy cost. Ocean pathways are promising, but many electrochemical routes require large pH swings, membranes/sorbents, and suffer from fouling. We report the self‐biased electro‐mineralization as a practical route to ocean carbon removal. Porous core‐shell electrodes program interfacial fields that direct Ca ²⁺ /CO ₃ ²⁻ transport and trigger in‐pore crystallization in simulated seawater, without membrane stacks or large bulk pH swings. Field strength is tunable via core/shell ratio, polymer chemistry, and fixed‐charge density, enabling the architecture to deliver long‐duration, fouling‐resistant operation (>2000 h), ∼25% DIC conversion under flow. A 400 cm ² cell and a simple 100‐liter stirred reactor show that the microscale, uniform field both preserves performance under geometry area scale‐up and enables low‐overhead capacity expansion. Techno‐economic analysis projects an energy consumption of 44 kJ mol ⁻¹ CO ₂ and a cost of $139 t ⁻¹ CO ₂ . Extending beyond CaCO ₃ , we precipitate additional sparingly soluble phases (CaF ₂ , BaSO ₄ , PbSO ₄ ) from complex brines, establishing a platform also supporting resource recovery. These results shift ocean mineralization from bulk‐solution manipulation to programmable reaction‐environment design, advancing a scalable, cost‐effective pathway to climate relevant carbon removal.