Photoelectrochemical generation of hydrogen and electricity from hydrazine hydrate using BiVO₄ electrodes

Abstract

This study demonstrates solar driven oxidation of hydrazine hydrate and the simultaneous production of hydrogen and electricity in photoelectrochemical cells and photofuel cells, respectively, using a visible light active molybdenum doped BiVO4 photoelectrode. The developed photoelectrodes exhibited tremendous efficiency towards anodic oxidation of hydrous hydrazine with continuous and stable hydrogen evolution at the Pt cathode under benign pH and zero bias conditions. Significantly, the photofuel cell containing hydrazine hydrate fuel has generated electricity with a high open circuit potential of 0.8 V. The presence of bicarbonate ions in the electrolyte has played a significant role in enhancing the kinetics of photoelectrochemical oxidation of hydrazine and improved the hydrogen and electricity generation efficiency thus avoiding the integration of an oxidation electrocatalyst. In addition, molybdenum doped BiVO4 as a possible photoelectrochemical hydrazine sensor has been investigated and the electrode photocurrent was found to be linearly dependent on the concentration of the hydrazine hydrate in the range of 20-90 mM with a correlation coefficient of 0.9936.

New application for the BiVO4 photoanode: A photoelectroanalytical sensor for nitrite

“…A recent study for hydrogen production allied with oxidation of hydrazine demonstrated photocurrent response at Mo doped BiVO 4 electrode dependent of hydrazine concentration. The holes (h + ) generated on Mo-BiVO 4 under visible light were able to oxidize the hydrazine [16]. Besides, to the best of our knowledge, there is no other report concerning the use of BiVO 4 as a photoelectrochemical sensor.…”

Visible‐Light‐Responsive TiO2/NiFe Mixed Metal Oxide‐Carbon Photocatalytic Fuel Cell with Synchronous Hydrogen Peroxide Production

“…[20,21] The PFC consists of a photoanode, a cathode and a reaction chamber with a certain proportion of fuel and electrolyte solution. TiO 2 , WO 3 , BiVO 4 , SnO 2 and Fe 2 O 3 were used as photoanode catalysts of PFC, [22][23][24][25][26][27][28][29][30][31] among which the TiO 2 was mostly employed. However, TiO 2 has some drawbacks during the PEC process, such as limited absorbance for visible light, rapid recombination of carriers, low charge transfer efficiency and so on.…”

Solar Cell with Photocatalyst Layers on Both the Anode and Cathode Providing an Electromotive Force of Two Volts per Cell

“…This paper limits the comparison to SCs comprising two photocatalysts on both electrodes. If platinum is used at the cathode, a V OC of 0.80–1.73 V and W max of 75–750 μW cm –2 are reported using FCs with a TiO 2 -based or BiVO 4 -based photoanode . Furthermore, based on photosynthesis, FCs using a tylakoid-C nanotube anode and Pt cathode generated a V OC of 0.4 V and W max of 5.3 μW cm –2 …”

“…If platinum is used at the cathode, a V OC of 0.80−1.73 V and W max of 75−750 μW cm −2 are reported using FCs with a TiO 2 -based 17 or BiVO 4 -based photoanode. 18 Furthermore, based on photosynthesis, FCs using a tylakoid-C nanotube anode and Pt cathode generated a V OC of 0.4 V and W max of 5.3 μW cm −2 . 19 In this study, to exceed a V OC of 2.0 V and achieve a W max higher than 70 μW cm −2 , higher-voltage-type SCs with photocatalysts on both electrodes were investigated using various nanocrystalline forms of TiO 2 .…”

“…A photocatalyst sample (0.135 g, Table 1a−f) was placed in a quartz photoreactor and evaluated at 295 K for 2 h at 10 −6 Pa. 1,28−32 Then, 18 O 2 photoexchange (0.55 kPa; 18 O 97.8%, chemical purity > 99.9%, Cambridge Isotope Laboratories, Inc.) with the photocatalyst was monitored at 295 K under irradiation by UV−visible light from a 500 W xenon arc lamp (Model SX-UID502XAM, Ushio). The distance between the exit of the lamp window and the photocatalyst was 160 mm.…”