Uniform Doping of Titanium in Hematite Nanorods for Efficient Photoelectrochemical Water Splitting

Abstract

Doping elements in hematite nanostructures is a promising approach to improve the photoelectrochemical (PEC) water-splitting performance of hematite photoanodes. However, uniform doping with precise control on doping amount and morphology is the major challenge for quantitatively investigating the PEC water-splitting enhancement. Here, we report on the design and synthesis of uniform titanium (Ti)-doped hematite nanorods with precise control of the Ti amount and morphology for highly effective PEC water splitting using an atomic layer deposition assisted solid-state diffusion method. We found that Ti doping promoted band bending and increased the carrier density as well as the surface state. Remarkably, these uniformly doped hematite nanorods exhibited high PEC performance with a pronounced photocurrent density of 2.28 mA/cm(2) at 1.23 V vs reversible hydrogen electrode (RHE) and 4.18 mA/cm(2) at 1.70 V vs RHE, respectively. Furthermore, as-prepared Ti-doping hematite nanorods performed excellent repeatability and durability; over 80% of the as-fabricated photoanodes reproduced the steady photocurrent density of 1.9-2.2 mA/cm(2) at 1.23 V vs RHE at least 3 h in a strong alkaline electrolyte solution.

Enhanced Charge Separation through ALD‐Modified Fe2O3/Fe2TiO5 Nanorod Heterojunction for Photoelectrochemical Water Oxidation

“…[11d] Compared to this nice work, we believe that ALD can provide a more controllable Fe 2 TiO 5 overlayer. It is noteworthy that ALD‐grown TiO 2 has been applied for hematite photoanodes in doping, surface passivation, and hole transfer enhancement . This paper reveals the effectiveness of ALD in constructing type‐II heterojunction for water splitting.…”

Current progress in developing metal oxide nanoarrays-based photoanodes for photoelectrochemical water splitting

“…[200]. [262,[399][400][401], Sn [402][403][404][405][406][407], Si [408], Zr [404], Ge [409], Se [410], Ta [411,412], W [413], and Nd [412]. Sn-doping could be achieved by simply annealing a-Fe 2 O 3 nanorod arrays at a higher tempera- under AM1.5 illumination).…”

Enhancing the Photoelectrochemical Performance of a Hematite Dendrite/Graphitic Carbon Nitride Nanocomposite through Surface Modification with CoFeOx

“…[8] However,t hese dopantsh aves hown little or no improvement in PEC activity of hematite with the exception of Si and Ti. [9,10] To date, welldefined a-Fe 2 O 3 nanostructures with variousm orphologies, such as 0D (nanoparticles), 1D (nanorods, nanowires, nanocables, and nanotubes), 2D/3D (disks,d endrites, flowers, and complicated hierarchical a-Fe 2 O 3 nanostructures), and hybrids have been fabricated. [11] Another approach, which shows remarkable improvement in PEC activity,i ss urface passivating the hematite by an oxygen evolution catalystw hich can efficientlys eparatee lectron-hole pairs.…”