As a p-type semiconductor CuBi2O4 is of potential interest as a photocathode or photocatalyst for the generation of hydrogen fuel by photoelectrochemical water splitting. Here we describe the preparation of CuBi2O4 nanocrystals by a hydrothermal approach. The formation of CuBi2O4 and its 1.7 eV band gap are confirmed by powder X-ray diffraction (XRD) and optical studies (UV-Vis spectroscopy). According to TEM the particles are irregular shaped with average particle size of 25.7 ± 4.7 nm. Surface photovoltage (SPV) measurements on CuBi2O4 nanoparticle films give positive photovoltage at &gt;1.7 eV photon energy, in agreement with hole majority carrier transport. The photovoltage is enhanced on fluorine-doped tin oxide (FTO) substrate and saturates at +0.21 V for 4,350 nm thick films. Photoelectrochemical scans on nanocrystal films immersed in 0.1 M K2SO4 aqueous solution at pH = 7 show photocathodic current of up to 6.45 μA cm-2 with an onset potential of +0.75 V vs. NHE in the presence of Na2S2O8 used as a sacrificial electron acceptor. Small amount of hydrogen is evolved under visible light when illuminated in the presence of sacrificial agent such as methanol. The significance of these findings will discuss the limitations of hydrogen evolution by CuBi2O4 photocatalyst from water.

Synthesis and limits of p-CuBi2O4 nanocrystals as visible light photocatalyst for hydrogen evolution from water

249th National Meeting (2015)

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