| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 726671 | Materials Science in Semiconductor Processing | 2014 | 7 Pages |
The metal organic framework (MOF) Cu3PO4(C2N3H2)2OH, synthesized by hydrothermal route, is characterized physically and photoelectrochemically. The compound crystallizes in a monoclinic symmetry with a layered structure. UV–visible spectroscopy shows an optical transition of 2.58 eV. The thermal variation of the electrical conductivity indicates a semiconducting behavior with a conduction mechanism dominated by small polaron hopping: σ=σ0 exp {0.44 eV/kT} and electron mobility (µ300 K=0.3 cm2 V−1 s−1) thermally activated. The interfacial capacitance at pH ~7 is characteristic of n type behavior with a flat band potential of +0.40 VSCE, an electrons density of 2×1015 cm−3 and a space charge region of 10 µm. The semicircle at high frequencies in the Nyquist plot is not centered on the real axis and the depletion angle (17°) is due to a constant phase element. The impedance data at low frequencies indicate a diffusion-controlled process. As application, the photochemical oxygen evolution is successfully achieved under visible light with a liberation rate of 0.70 cm3 min−1 g−1 and a quantum yield of 0.13%. The reaction (2SO32−+H2O→S2O32−S2O32−+O2+2OH, ΔG0=90.68 kcal mol−1) can be evaluated for the chemical storage.
