Improved O₂ evolution from a water splitting reaction over Er³⁺ and Y³⁺ co-doped tetragonal BiVO₄

Abstract

Erbium-yttrium co-doped BiVO 4 with a tetragonal structure is synthesized by means of a surfactant free hydrothermal method. The studied photocatalyst shows good photoactivity under sun-like excitation for the degradation of methylene blue (MB) and for O 2 evolution. From structural and morphological characterization, it has been stated that the presence of lanthanides induces the stabilization of the tetragonal phase. This is probably due to the substitutional occupation that occurs in the BiVO 4 lattice. The photocatalytic performance under visible-NIR radiation clearly evidences the occurrence of an up-conversion process involved in the overall photo-electronic mechanism. The tetragonal phase ) under sun-like excitation, being 8 times higher than that attained for m-BiVO 4 (53 μmol g −1 h −1).

Photocatalytic Escherichia coli inactivation by means of trivalent Er 3+ , Y 3+ doping of BiVO 4 system

“…The Er 3+ , Y 3+ codoping can be an interesting strategy to improve the electronic charge separation process, enhancing the UV-photoassisted process and a small contribution of vis-NIR photons to UV-active tetragonal co-doped BiVO4 that probably could take place due to an energy transfer process from erbium ions, as have been reported by other authors [17]. Therefore, a multi-approach improvement of the BiVO4 photoactivity can be achieved by simultaneous doping with trivalent ion doping such as Y 3+ , Er 3+ or Yb 3+ [15].…”

“…In addition to the observed tetragonal stabilization, the incorporation of erbium and yttrium ions induces important structural modifications. As it has being previously reported by observing the evolution of the cell features obtained from Rietveld refinement with different erbium and yttrium content, the incorporation of these dopants 10 into the BiVO4 structure takes place in different ways [16,17]. Whereas the monoclinic unit cell volume exhibits a slight increase as dopant ions are incorporated, for the tetragonal one a slight reduction in the cell volume is attained, suggesting a different location of the dopant in each BiVO4 crystalline phase.…”

“…Thereby, when BiVO4 is doped with Er 3+ or Y 3+ cations, the obtained vanadates show a heterogeneous structure formed by a tetragonal and monoclinic phase mixture. As previously stated, the incorporation of yttrium and erbium dopant ions into the BiVO4 structure induces the stabilization of the tetragonal phase [17,22]. Since yttrium content is present in higher amount with respect to erbium, the tetragonal phase stabilization is more pronounced for the Y 3+ -doped system [11,16].…”

Chemically induced porosity on BiVO4 films produced by double magnetron sputtering to enhance the photo-electrochemical response

“…31 The structural information of BiVO 4 is obtained from the band centered at 210 cm À1 . The asymmetric and symmetric formations of the VO 4 tetrahedron are given by the bands centered at 324 and 366 cm À1 , respectively.…”

Hydrothermal Preparation and Characterization of TiO2/BiVO4 Composite Catalyst and its Photolysis of Water to Produce Hydrogen

“…Figure (a) is for the sample without bismuth vanadate, showing a significant vibration peak at 143 cm −1 only, which is attributed to the E g mode of titanium dioxide anatase. In all bismuth vanadate samples, vibration peaks at about 121, 207, 327, 364 and 821 cm −1 are observed, which belong to characteristic vibrational modes of bismuth vanadate .…”