Highly Efficient Photocatalytic Z-Scheme Hydrogen Production over Oxygen-Deficient WO3–x Nanorods supported Zn0.3Cd0.7S Heterostructure

Abstract

The demand for clean renewable energy is increasing due to depleting fossil fuels and environmental concerns. Photocatalytic hydrogen production through water splitting is one such promising route to meet global energy demands with carbon free technology. Alternative photocatalysts avoiding noble metals are highly demanded. Herein, we fabricated heterostructure consist of oxygen-deficient WO3–x nanorods with Zn0.3Cd0.7S nanoparticles for an efficient Z-Scheme photocatalytic system. Our as obtained heterostructure showed photocatalytic H2 evolution rate of 352.1 μmol h−1 with apparent quantum efficiency (AQY) of 7.3% at λ = 420 nm. The photocatalytic hydrogen production reaches up to 1746.8 μmol after 5 hours process in repeatable manner. The UV-Visible diffuse reflectance spectra show strong absorption in the visible region which greatly favors the photocatalytic performance. Moreover, the efficient charge separation suggested by electrochemical impedance spectroscopy and photocurrent response curves exhibit enhancement in H2 evolution rate. The strong interface contact between WO3–x nanorods and Zn0.3Cd0.7S nanoparticles ascertained from HRTEM images also play an important role for the emigration of electron. Our findings provide possibilities for the design and development of new Z-scheme photocatalysts for highly efficient hydrogen production.

Modular Design of Noble‐Metal‐Free Mixed Metal Oxide Electrocatalysts for Complete Water Splitting

“…Theo bservation of Cu + and Cu 2+ could indicate two distinct copper-containing phases,f or example, Cu 2 Oa nd aC u 2+ -containing (amorphous) metal oxide. [37][38][39] In sum, this materials analysis suggests that amixed metal oxide phase is present containing crystalline Cu 2 Op articles together with amorphous,h ydrated copper, cobalt and tungsten oxide phases.T he exact structural properties of this complex system will be further explored using spectroscopic,magnetometric,diffractometric and theoretical methods in subsequent studies. [36,37] Thed econvoluted O1s spectrum indicates the presence of oxygen-metal bonds (O À Co,O À Cu, O À W) and hydroxyl groups (O À H).…”

N,Fe-Doped Carbon Dot Decorated Gear-Shaped WO3 for Highly Efficient UV-Vis-NIR-Driven Photocatalytic Performance

“…The space between the interlayers of G-WO3 could accommodate CDs, and the vacant spaces between these protruding nanorods on G-WO3 made it more mesoporous, allowing it to better couple with CDs. [30]. No diffraction peaks for the CDs could be detected in the composites because of their low content.…”

“…N,Fe-CDs could be clearly observed on the surface of G-WO3, as shown in Figure 1e. As illustrated in Figure 1f, the high resolution transmission electron microscopy images (HRTEM) of G-WO3 displayed an obvious lattice fringe with a lattice distance of 0.39 nm corresponding to the (001) lattice plane of WO3 [30], and the N,Fe-CDs displayed an obvious lattice fringe with a lattice spacing of 0.32 nm.…”

Assembly of Ultra‐Thin NiO Layer Over Zn1−xCdxS for Stable Visible‐Light Photocatalytic Overall Water Splitting

“…However, the Zn 1− x Cd x S solid solution catalysts still suffer from photocorrosion during the photocatalytic process. Some strategies have been developed to overcome this drawback, such as fabricating heterojunctions in Zn 1− x Cd x S, constructing a Z‐Scheme structure, and using hole scavengers . The assembly of a protection layer over Zn 1− x Cd x S catalyst is an effective method to improve photocorrosion resistance.…”