NOVELTY - Making a silica sol-gel derived monolith, comprises: hydrolyzing a silicon dioxide precursor with water in the presence of a catalyst to form a sol; gelling the sol; and drying the gelled sol, where the catalyst is preselected to obtain a porous silicon dioxide-containing monolith having a pore volume of 0.3-2 cm3/g and a predetermined average pore diameter of 0.3-30 nm with at least 60% of pores having a pore size within 20% of the average pore size.    USE - The method is useful for making a nanoporous silica sol-gel derived monolith, which is useful as a high surface area substrate or template and high surface area electrode. The sol-gel wafer having cross-sectional dimensions of an electrode is useful in a capacitor, an ultracapacitor, a battery or a fuel cell (all claimed). The sol-gel derived monoliths are useful in filtration apparatus, optical materials and sensors.    ADVANTAGE - The silica sol-gel derived monolith has a predetermined average pore diameter of 0.3-10 nm with at least 60% of pores having a pore diameter within 20% of the average pore size.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a silica sol-gel derive monolith prepared by the method;    (2) a method-2 for forming a sol-gel derived monolith, comprising reacting a sol-gel precursor and water in the presence of a catalyst to form a wet gel and drying the wet gel to form the sol-gel derived monolith, where a molar ratio of the hydrofluoric acid relative to the sol-gel precursor is selected to achieve a preselected average pore size and/or pore size distribution in the sol-gel derived monolith;    (3) a sol-gel derived monolith prepared by the method-2;    (4) a method for making a silica sol-gel monolith, comprising either: reacting a silica sol-gel precursor with water in the presence of a catalyst and tuning an average pore size and/or a pore size distribution in the silica sol-gel monolith by controlling a rate of pore formation with the catalyst, where a combined molar ratio of the acids relative to a silica sol-gel precursor is 0.02:1 or less; or tuning an average pore size and/or a pore size distribution in a silica sol-gel monolith by reacting a silica sol-gel precursor with water in the presence of a catalyst and controlling a rate of pore formation with the catalyst and at least one of the hydrofluoric acid and the second acid is present at a molar ratio relative to the precursor that is 0.001:1 or less;    (5) a nanoporous silica sol-gel derived monolith having a pore volume of 0.3-2 cm3/g and an average pore diameter of 0.3-30 nm with at least 60% of the pores having a size within 20% of the mean pore dimension;    (6) a mold for casting silica sol-gel wafers comprising a container comprising multiple slots, each slot comprising opposing, closely-spaced parallel sidewalls and hydrophobic inner surfaces;    (7) a method of casting silica sol-gel wafers, comprising: casting a gel formulation into a mold comprising the container, where the gel formulation comprises a silicon dioxide precursor, water and a catalyst; allowing the gel formulation to form a gel in the slots in the mold; and drying the gels to form silica sol-gel wafers in the slots of the mold or after being removed from the mold; and    (8) a method for making a sol-gel derived monolith, comprising monitoring a physical dimension of the monolith to determine an extent of reaction.