“…The sol-gel technique is an attractive approach for preparing micro/ mesoporous oxide materials as powders, membranes and filters with high purity and homogeneity due to its flexibility and low temperature preparation of sols and gels [3]. A number of sol-gel processes to prepare highly porous nonoxide ceramics have also been reported, e.g., boron nitride [4][5][6][7][8], metal (carbo)nitrides [9][10][11][12][13][14], silicon carbonitride [15][16][17][18][19][20][21] and boron carbonitride [22,23]. A sol-gel process in an ammono-system has been used to prepare polymeric boron-, titano-and tantalo-silazanes by controlled co-ammonolysis of the elemental alkylamides [24].…”