Characteristic, electrical and optical properties of potassium borate (KB5O8·4H2O) hydrothermally synthesized from different boron sources

Potassium borate was hydrothermally synthesized from various boron minerals (H 3 BO 3 , B 2 O 3 , Na 2 B 4 O 7 ·5H 2 O and Na 2 B 4 O 7 ·10H 2 O) at reaction conditions of 60–90 °C and 15–120 min. The synthesized potassium borate was identified as “santite (KB 5 O 8 ·4H 2 O)” from the X-ray diffraction (XRD) analyses results. The specific band values between B and O atoms were characterized by Fourier transform infrared and Raman spectroscopies. Multiangular particles were generally observed in the range of 3.41 μm–234.94 nm. The use of different boron sources affected the morphology. Higher reaction yields were determined in the use of boric acid (H 3 BO 3 ). Optical absorption of potassium borate minerals was approximately 340 nm. AC and DC electrical properties of materials were determined by using current–voltage and capacitance voltage characteristics. Electrical resistivity values of DC were found in the range of 4.17 × 10 8 –4.07 × 10 10 Ω cm, whereas dielectric constants of AC were between 2 × 10 5 and 2 × 10 6 .