The construction of rapid prototyping for structured ceramics has a promoting effect on potential applications. In this work, engineering slurry with different formulations were used to develop aqueous colloidal ceramic slurry for direct ink writing (DIW). Optimized slurry of Formulation 5 possessed good printing effect for DIW with stable mechanical properties. Related characteristics, including shrinkage, compressive strength, rheological behavior, and chemical property, were also examined. DIW ceramics prepared from optimized slurry can be preliminarily applied to adsorption of Rhodamine B and chlortetracycline, and possessed the advantages of easy separation and operation compared with powder adsorbents. This work provides a strategy for the design of 3D-printed kaolin ceramic slurry, and also extends to potential application in adsorption.

Integrating semiconductor photocatalysts with outstanding visible light absorption and fast surface/interface charge transfer kinetics is still an enormous challenge for efficient CO₂ photoreduction. In this work, the Au nanoparticles have been coupled with ultrathin BiOBr nanosheets, the formed heterostructure (Au/BiOBr) possesses a localized surface plasmon resonance (LSPR) and enhances the visible light absorption ability, as well as forms a fast charge transport channel on the interface between Au and BiOBr. Thus, the heterostructure photocatalyst exhibits higher photocatalytic CO₂ to CO performance (135.3/16.43 μmol g⁻¹) than that of BiOBr (89.0/6.46 μmol g⁻¹) under 300 W Xe lamp and visible light (λ > 400 nm) irradiation for 5 h, respectively. Finally, the in situ FT-IR spectroscopy revealed CO₂ photoreduction process and found that the *COOH is the key intermediate for CO₂ to CO. This work provides an effective method to construct multielectron transfer scheme for efficient photocatalytic CO₂ reduction.