Abstract: A method of capturing water from a composition comprising water or water vapour using a hybrid ultramicroporous material. The method comprises the steps of: (a) providing a hybrid ultramicroporous material of formula [M(L)a(X)b]; and (b) contacting the hybrid ultramicroporous material with the composition comprising water to capture water into the hybrid ultramicroporous material; The hybrid ultramicroporous materials used in the method of the present invention have fast kinetics of water uptake and high working capacity compared to known commercial sorbent materials. The method of the present invention may be used in water capture and purification processes to provide fresh water suitable for drinking or for use in agriculture. The method of the present invention may also be used to remove water as a contaminant or for use in dehumidification processes. A use of such a hybrid ultramicroporous material and a device for capturing water are also disclosed.