Modulated Ultrathin NiCo-LDH Nanosheet-Decorated Zr3+-Rich Defective NH2-UiO-66 Nanostructure for Efficient Photocatalytic Hydrogen Evolution

Saddam Sk; Aparna Jamma; Deepak S Gavali; Vidha Bhasin; Rajib Ghosh; Kathi Sudarshan; Ranjit Thapa; Ujjwal Pal

doi:10.1021/acsami.3c13009

Modulated Ultrathin NiCo-LDH Nanosheet-Decorated Zr³⁺-Rich Defective NH₂-UiO-66 Nanostructure for Efficient Photocatalytic Hydrogen Evolution

ACS Appl Mater Interfaces. 2023 Dec 6;15(48):55822-55836. doi: 10.1021/acsami.3c13009. Epub 2023 Nov 23.

Authors

Saddam Sk^{1

2}, Aparna Jamma^{1

2}, Deepak S Gavali³, Vidha Bhasin⁴, Rajib Ghosh⁵, Kathi Sudarshan⁶, Ranjit Thapa³, Ujjwal Pal^{1

2}

Affiliations

¹ Department of Energy & Environmental Engineering, CSIR-Indian Institute of Chemical Technology, Hyderabad 500007, India.
² Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
³ Department of Physics, SRM University AP, Amaravati 522240, Andhra Pradesh, India.
⁴ Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
⁵ Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
⁶ Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India.

PMID: 37994833
DOI: 10.1021/acsami.3c13009

Abstract

Defect engineering through modification of their surface linkage is found to be an effective pathway to escalate the solar energy conversion efficiency of metal-organic frameworks (MOFs). Herein, defect engineering using controlled decarboxylation on the NH₂-UiO-66 surface and integration of ultrathin NiCo-LDH nanosheets synergizes the hydrogen evolution reaction (HER) under a broad visible light regime. Diversified analytical methods including positron annihilation lifetime spectroscopy were employed to investigate the role of Zr³⁺-rich defects by analyzing the annihilation characteristics of positrons in NH₂-UiO-66, which provides a deep insight into the effects of structural defects on the electronic properties. The progressively tuned photophysical properties of the NiCo-LDH@NH₂-UiO-66-D-heterostructured nanocatalyst led to an impressive rate of HER (∼2458 μmol h^-1 g^-1), with an apparent quantum yield of ∼6.02%. The ultrathin NiCo-LDH nanosheet structure was found to be highly favored toward electrostatic self-assembly in the heterostructure for efficient charge separation. Coordination of Zr³⁺ on the surface of the NiCo-LDH nanosheet support through NH₂-UiO-66 was confirmed by X-ray absorption spectroscopy and electron paramagnetic resonance spectroscopy techniques. Femtosecond transient absorption spectroscopy studies unveiled a photoexcited charge migration process from MOF to NiCo-LDH which favorably occurred on a picosecond time scale to boost the catalytic activity of the composite system. Furthermore, the experimental finding and HER activity are validated by density functional theory studies and evaluation of the free energy pathway which reveals the strong hydrogen binding over the surface and infers the anchoring effect of the ultrathin layered double hydroxide (LDH) in the vicinity of the Zr cluster with a strong host-guest interaction. This work provided a novel insight into efficient photocatalysis via defect engineering at the linker modulation in MOFs.

Keywords: DFT; H2 production; NH2−UiO-66; PALS; defect engineering; fs-TAS; ultrathin NiCo-LDH nanosheet.