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Zeolites, silica-supported amines, and metal–organic frameworks (MOFs) have been demonstrated as promising adsorbents for direct air CO2capture (DAC), but the shaping and structuring of these materials into sorbent modules for practical processes have been inadequately investigated compared to the extensive research on powder materials. Furthermore, there have been relatively few studies reporting the DAC performance of sorbent contactors under cold, subambient conditions (temperatures below 20 °C). In this work, we demonstrate the successful fabrication of adsorbent monoliths composed of cellulose acetate (CA) and adsorbent particles such as zeolite 13X and MOF MIL-101(Cr) by a 3D printing technique: solution-based additive manufacturing (SBAM). These monoliths feature interpenetrated macroporous polymeric frameworks in which microcrystals of zeolite 13X or MIL-101(Cr) are evenly distributed, highlighting the versatility of SBAM in fabricating monoliths containing sorbents with different particle sizes and density. Branched poly(ethylenimine) (PEI) is successfully loaded into the CA/MIL-101(Cr) monoliths to impart CO2uptakes of 1.05 mmol gmonolith–1at −20 °C and 400 ppm of CO2. Kinetic analysis shows that the CO2sorption kinetics of PEI-loaded MIL-101(Cr) sorbents are not compromised in the monoliths compared to the powder sorbents. Importantly, these monoliths exhibit promising working capacities (0.95 mmol gmonolith–1) over 14 temperature swing cycles with a moderate regeneration temperature of 60 °C. Dynamic breakthrough experiments at 25 °C under dry conditions reveal a CO2uptake capacity of 0.60 mmol gmonolith–1, which further increases to 1.05 and 1.43 mmol gmonolith–1at −20 °C under dry and humid (70% relative humidity) conditions, respectively. Our work showcases the successful implementation of SBAM in making DAC sorbent monoliths with notable CO2capture performance over a wide range of sorption temperatures, suggesting that SBAM can enable the preparation of efficient sorbent contactors in various form factors for other important chemical separations.

The crystal quality of a Cu2ZnSn(S,Se)4(CZTSSe) thin film is crucially important to a high-performance CZTSSe solar cell. After selenization, a bilayer CZTSSe thin film consisting of a large-grain top layer and a small-particle bottom layer is usually observed according to the literature. In this work, a facile air-annealing pretreatment is conducted for a Cu2ZnSnS4precursor thin film prior to selenization, which can lead to sodium diffusion into the CZTS precursor thin film and surface oxidization of the CZTS thin film. Our experimental results revealed that the Na prediffusion and the surface oxidation of the CZTS precursor thin film can significantly promote the crystal growth of the CZTSSe thin film, which can completely remove the small-particle bottom layer and form a large-grain-spanned CZTSSe thin film. As a result, a photoelectric conversion efficiency of 9.80% was achieved by this method.