A crystalline and 3D periodically ordered mesoporous quaternary semiconductor for photocatalytic hydrogen generation

Abstract

We have prepared the first crystalline and 3D periodically ordered mesoporous quaternary semiconductor photocatalyst in an evaporation-induced self-assembly assisted soft-templating process. Using lab synthesized triblock-terpolymer poly(isoprene-b-styrene-b-ethylene oxide) (ISO) a highly ordered 3D interconnected alternating gyroid morphology was achieved exhibiting near and long-range order, as evidenced by small angle X-ray scattering (SAXS) and electron microscopy (TEM/SEM). Moreover, we reveal the formation process on the phase-pure construction of the material's pore-walls with its high crystallinity, which proceeds along a highly stable W compound, by both in situ and ex situ analyses, including X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR) and electron paramagnetic resonance (EPR). The resulting photocatalyst CsTaWO with its optimum balance between surface area and ordered mesoporosity ultimately shows superior hydrogen evolution rates over its non-ordered reference in photocatalytic hydrogen production. This work will help to advance new self-assembly preparation pathways towards multi-element multifunctional compounds for different applications, including improved battery and sensor electrode materials.

Ordered mesoporous metal oxides for electrochemical applications: correlation between structure, electrical properties and device performance

“…This result was explained by transport limitations, as the water/methanol mixture used as electrolyte was partly confined in the small pores due to capillary forces, blocking the release of gas bubbles. 256 Furthermore, comparison between samples with (large-pore) ordered and disordered mesoporous structures revealed higher H 2 evolution rates for the former material, despite having a lower specific surface area (Fig. 23).…”

Mesoporous Semiconductors: A New Model To Assess Accessible Surface Area and Increased Photocatalytic Activity?

“…presented ordered mesoporous CsTaWO6 with mesopores around 40 nm in size (Figure 4b). 75 Comparing both mesoporous CsTaWO6, the ordered mesoporous material showed 300% increased activity in hydrogen production albeit reduced surface area. This shows that even with decreased surface area strong activity enhancements can be achieved when large mesopores for improved mass transport are established in semiconductor oxide materials.…”

Mesoporous NiFe2O4 with Tunable Pore Morphology for Electrocatalytic Water Oxidation

“…Mesoporous NiFe 2 O 4 samples were prepared using the well-known EISA process, [81] coupled with the addition of citric acid during the synthesis, inspired by the works of Kraehnert et al [31,43] Therefore, 116.3 mg (0.4 mmol) nickel(II) nitrate hexahydrate (SigmaAldrich, 99.999 %) were dissolved in 2 mL of deionized water, and stirred for 10 minutes (500 rpm). Afterwards, 323.2 mg (0.8 mmol) iron(III) nitrate nonahydrate (AcrosOrganics, 99 + %) were added, followed by stirring for 1 hour.…”