Metal-organic frameworks (MOFs) have attracted much attention in the past decades owing to their amazing properties, including rich surface chemistry, flexible porous structure, and superior surface area. MOFs are conventionally synthesized via wet-chemistry methods, which, however, suffer from long reaction durations and inhomogeneous mixing. To address these issues, we have developed a microdroplet-based nanomanufacturing process to fabricate MOFs-based powder materials with controlled nanostructures in a rapid, continuous, and scalable manner. The mechanisms of MOFs formation inside the microdroplets were investigated by experimental and theoretical approaches. Further, we have also developed strategies to integrate MOFs with semiconductors to form hybrid photocatalysts for environmental applications, such as gas adsorption, CO2 photoreduction, and pollutant degradation. The quantitative pathways of gas adsorption, activation, and charge transfer within the hybrid nanostructures were explored by various in-situ techniques, such as diffuse reflectance infrared Fourier transform spectroscopy and X-ray photoelectron spectroscopy, coupled with density functional theory calculations.