Chemicals and equipment used in this study.
| Materials and equipment | Purity and brand |
|---|---|
| Bentonite stone | Sigma Aldrich (≥99.995%) |
| Guanidine | Sigma Aldrich (99.9%) |
| FeCl2·4H2O | Sigma Aldrich (98%) |
| FeCl3·6H2O | Sigma Aldrich (≥98%) |
| K2CO3 | Merck (98%) |
| Sodium hydroxide | Merck (97%) |
| Ethanol | Sigma Aldrich (97%) |
| Acetonitrile | Merck (98%) |
| Sodium borohydride | Sigma Aldrich (≥96%) |
| FT-IR analysis | Shimadzu IR-470 spectrometer |
| EDX analysis | Numerix DXP-X10P |
| SEM analysis | Sigma-Zeiss microscope |
| TEM analysis | Philips Cm 12 instrument |
| XRD analysis | JEOL JDX-8030 (30 kV, 20 mA) |
| NMR analysis | Varian Unity Inova 500 MHz |
| Ultrasound cleaning bath | KQ-250 DE (40 kHz, 250 W) |
| Melting point measurement | Electrothermal 9100, made in UK |