Improved photoelectrochemical responses of Si and Ti codoped α-Fe2O3 photoanode films

Abstract

We studied photoelectrochemical performance of the undoped, Si-doped, Ti-doped, and codoped α-Fe2O3 film prepared by ultrasonic spray pyrolysis. Since the ions radius of Si4+<Fe3+<Ti4+, Si and Ti codoping can balance the ion radius difference between Fe3+ and Si4+ (or Ti4+) and increase the donor concentration. Their donor concentrations, calculated from slopes of the Mott–Schottky plots, are 9.10×1018 cm−3, 1.89×1020 cm−3, 2.04×1020 cm−3, and 7.06×1020 cm−3, respectively. Incident photon to current efficiency of the codoped film is 34% at 365 nm and 0.6 V versus Ag/AgCl, much higher than 10%, 20%, and 22% for the undoped, Si-doped, and Ti-doped film, respectively.

Fabrication of cation-doped BaTaO2N photoanodes for efficient photoelectrochemical water splitting under visible light irradiation

“…The enhanced PEC efficiencies via cation-doping have been indeed reported in some semiconductor photoanodes [20][21][22][23][24][25][26] and photocathodes, 27,28 while such reports are basically limited to metal oxide semiconductors. [20][21][22][23][24][25][26][27] ) into the Ta 5+ sites, were prepared via thermal ammonolysis of the corresponding oxide precursors. 14,29 The metal sources were added into a methanol (30 ml) with the ratio of Ba: Ta: M = 1: (1 − x): x, in which the molar amount of Ba was fixed to be 12 mmol and the x values were ranged from 2 to 7.…”

Activation of Hematite Nanorod Arrays for Photoelectrochemical Water Splitting

“…First, all of the films displayed a flat band potential of ~0.4 V vs RHE regardless of the annealing condition, which is consistent with literature reports for hematite thin films. [24,25] Somewhat surprising is that the slope in the linear region was largely unaffected by the choice of annealing conditions, varying by no more than a factor of 3.…”

“…These are among the lowest onset potentials achieved for hematite photoanodes without an OER catalyst, [9,23] about 250 mV lower than many reports. [2,17,20,24] The low potential may indicate the annealed anodes contain minimal surface trapping states. [22,23] The J OER recorded as a function of annealing time and temperature is reported in the inset of Fig.…”

“…Most leading hematite electrodes are highly doped compounds, and numerous elements (Si, Ti, Pt, Cr, Mo, Al) have been shown to be beneficial. [11,17,18,[23][24][25]33] High levels of doping reduce the Debye length in hematite to below 1 nm, which has been suggested to improve charge transport and separation. [24] To further investigate the role of doping a Mott-Schottky analysis was performed at 500 Hz (Fig.…”

Tin doped indium oxide core—TiO2 shell nanowires on stainless steel mesh for flexible photoelectrochemical cells

“…3-5 A great amount of efforts are being devoted to developing photoanodes (i.e., increasing surface area and reducing band gap of semiconductors) to effectively harvest more visible light. [6][7][8][9] However, currently available devices still exhibit moderate performance, due to the short hole diffusion length and the trade-off relationship between surface area and charge collection. [10][11][12] Highly conductive oxide core-thin photoanode materials shell nanowire (NW) structure can be a solution to the problems associated surface area and charge collection.…”