Metal–Organic Frameworks Derived Plasmonic Catalyst with Full Spectral Response for Photoelectrochemical Water Splitting Enhancement

Abstract

Water splitting through photoelectrochemical (PEC) catalytic reaction holds significant promise for energy conversion. However, the low energy‐storage efficiency severely hinders the practical applications owing to the narrow spectral absorption and adverse charge recombination. Herein, a plasmon‐enhanced catalyst, integrating metal–organic frameworks (MOFs)‐derived Cd0.8Zn0.2S with Ag/Au hollow porous nanoshells (Ag/Au HPNSs), is rationally designed to afford Ag/Au HPNS‐Cd0.8Zn0.2S nanoshells (Ag/Au HPNS‐Cd0.8Zn0.2S NSs), which extends the absorption range from the ultraviolet to the near‐infrared region. The PEC performance shows that the photocurrent of the anode exhibits an approx. tenfold enhancement and full spectral response compared with the intrinsic ZIF‐8 dodecahedrons. More detailed exploration and theoretical simulations find that the MOFs‐derived Cd0.8Zn0.2S, with a high dielectric constant, can markedly prevent the decay of the plasmon fringing field and broaden the interaction range of the electromagnetic field. Such a synergistic effect finally improves the charge separation efficiency and results in the superior PEC performance of the photoanode. This work offers a new method for the construction of efficient PEC catalysts and provides new insights into the understanding of the plasmonic effect on catalytic reactions.

Engineering a non-noble plasmonic center in MOF-derived Z-scheme heterojunctions for enhanced photoelectrochemical water splitting

“…where J is the photocurrent density (mA cm −2 ), λ is the wavelength of the monochromatic light (nm), and P is the light intensity (mW cm −2 ). 41 As displayed in Fig. 6c, the IPCE value of TiO 2 @NH 2 -MIL-125 was much higher due to the excellent light-harvesting ability and improved charge separation originating from the Z-scheme configuration.…”

“…To obtain the solar energy conversion efficiency of the catalysts, the incident photon-to-electron conversion efficiency (IPCE) was evaluated according to the following eqn (1):where J is the photocurrent density (mA cm −2 ), λ is the wavelength of the monochromatic light (nm), and P is the light intensity (mW cm −2 ). 41 As displayed in Fig. 6c, the IPCE value of TiO 2 @NH 2 -MIL-125 was much higher due to the excellent light-harvesting ability and improved charge separation originating from the Z-scheme configuration.…”

“…7a) using the following formula (2):where ε r and ε 0 are the permittivity of samples and vacuum, respectively, and C is the capacitance. 41 The N D values of TiO 2 @NH 2 -MIL-125 and TiO 2 @NH 2 -MIL-125@R-STO were calculated to be about 4.9 × 10 27 m −3 and 1.3 × 10 28 m −3 , which were much higher than that of pristine TiO 2 (5.6 × 10 26 m −3 ). Furthermore, from the open-circuit voltage–time curves (OCP, Fig.…”

Metal–organic Framework-Derived CoSx/NiS Co-Decorated Heterostructures: Toward Simultaneous Acceleration of Charge Carrier Separation and Catalytic Kinetics

“…Metal–organic frameworks (MOFs), constructed by joining organic linkers and metal-containing units by strong bonds, are recently a promising hard template to tailor single atomic active metal centers. , The intrinsic superiority of atomic metal building blocks linking with organic ligands makes MOFs excellent candidates to achieve in situ derivation and homogeneous dispersion of active centers on the lattice level. , Inspired by this, herein, an MOF-derived CoS x /NiS co-decorated heterostructure (TiO 2 /CdS/CoS x /NiS) was first synthesized via multistep in situ derivatization of TiO 2 @CoNi MOF. The in situ derivatization led to a homogeneous dispersion of CoS x /NiS in the heterojunction, which effectively accelerated the catalytic kinetics and improved the catalytic active center without visible agglomeration after stability tests.…”