One-Compartment InGaN Nanowire Fuel Cell in the Light and Dark Operating Modes

Abstract

A one-compartment H 2 O 2 photofuel cell (PFC) with a photoanode based on InGaN nanowires (NWs) is introduced for the first time. The electrocatalytic and photoelectrocatalytic properties of the InGaN NWs are studied in detail by cyclic voltammetry, current versus time measurements, photovoltage measurements, and electrochemical impedance spectroscopy. In parallel, IrO x (OH) y as the co-catalyst on the InGaN NWs is evaluated to boost the catalytic activity in the dark and light. For the PFC, Ag is the best as the cathode among Ag, Pt, and glassy carbon. The PFC operates in the dark as a conventional fuel cell (FC) and under illumination with 25% increased electrical power generation at room temperature. Such dual operation is unique, combining FC and PFC technologies for the most flexible use.

InN/InGaN Quantum Dot Abiotic One-Compartment Glucose Photofuel Cell: Power Supply and Sensing

“…To this end, we compare the performance of a PFC with an Ag cathode, which might have a higher reduction potential, such as for the reduction of H 2 O 2 . 27 The Ag cathode, however, produces a lower photocurrent density and a lower output power density, as shown in Supporting Information Figure S4. The open-circuit cell voltage for the Ag cathode is comparable to that for the Pt cathode.…”

“…Glucose is not that easily oxidized in the dark by the InN/InGaN QDs as H 2 O 2 by InGaN nanowires (NWs). 27 …”

“…This increases the potential difference with the reduction potential of the Pt cathode, which determines the open-circuit cell voltage, together with the photovoltage. To this end, we compare the performance of a PFC with an Ag cathode, which might have a higher reduction potential, such as for the reduction of H 2 O 2 . The Ag cathode, however, produces a lower photocurrent density and a lower output power density, as shown in Supporting Information Figure S4.…”

“…For glucose, there is no significant FC operation in the dark. Glucose is not that easily oxidized in the dark by the InN/InGaN QDs as H 2 O 2 by InGaN nanowires (NWs) …”

Hydrogen peroxide photo-fuel cells

“…Nötzel and coworkers have reported a one compartment-H 2 O 2 -PFC with the structure of IrO x (OH) y /InGaN nanowire array/Si ( photoanode) | 0.5 M Na 2 SO 4 + 0.5 M H 2 O 2 | Ag wire (cathode). 38 The H 2 O 2 -PFC showed a J sc of 2.75 mA cm −2 , V oc of 0.24 V, and P max of ∼0.16 mW cm −2 under the illumination of simulated sunlight (AM 1.5, one sun). Interestingly, this PFC can operate even in the dark as a conventional FC.…”