김형일 교수

Size controlled nanographene oxides (NGOs; <50 nm) were prepared by a two-step oxidation process and NGOs were self-assembled with TiO2 nanoparticles to form the core/shell structure. Nanosized GO-coated TiO2 nanoparticles (NGOTs) were then reduced by a photocatalytic process under UV irradiation to obtain graphene-coated TiO2. This is clearly different from the typical graphene/TiO2 composite with the particles-on-a-sheet geometry and is the first study on the core/shell structure of its kind.

The composite of different semiconductor nanoparticles may facilitate the charge separation and transfer because the difference in the band edge positions creates the potential gradient at the composite interface. For this purpose, the CdS–TiO2–WO3 ternary hybrid was successfully synthesized and characterized for the structural, optical, and morphological properties by X-ray diffraction, diffuse reflectance UV/visible absorption spectroscopy, high-resolution transmission electron micrography, an

This study demonstrates, for the first time in literature, <italic>in situ</italic> photocatalytic synthesis of hydrogen peroxide (H₂O₂) through sensitized triplet–triplet annihilation (TTA) upconversion (UC) of low-energy, sub-bandgap photons.

Thin amorphous TaO_xN_y layer-coated <italic>N</italic>-doped TiO₂ nanotubes successfully serve as a water splitting photoanode.

Proper co-catalysts (usually noble metals), combined with semiconductor materials, are commonly needed to maximize the efficiency of photocatalysis. Search for cost-effective and practical alternatives for noble-metal co-catalysts is under intense investigation. In this work, nanodiamond (ND), which is a carbon nanomaterial with a unique sp(3)(core)/sp(2)(shell) structure, was combined with WO3 (as an alternative co-catalyst for Pt) and applied for the degradation of volatile organic compounds u

A phosphate (P)- and Mo-modified BiVO₄ photoanode and AQ-modified carbon cathode achieve efficient and durable photoelectrochemical production of H₂O₂ through dual processes.

This study demonstrates the first reported photocatalytic decomposition of an indoor air pollutant, acetaldehyde, using low-energy, sub-bandgap photons harnessed through sensitized triplet-triplet annihilation (TTA) upconversion (UC). To utilize low-intensity noncoherent indoor light and maximize photocatalytic activity, we designed a plasmon-enhanced sub-bandgap photocatalyst device consisting of two main components: (1) TTA-UC rubbery polymer films containing broad-band plasmonic particles (Ag

Plastic waste poses a significant environmental threat due to its widespread use and disposal, necessitating innovative upcycling methods. Here, we introduce alkalinized carbon nitride (Alk-CN) as an efficient photocatalyst for the solar-driven photoreforming of polyethylene terephthalate (PET) into hydrogen peroxide (H 2 O 2 ) in alkaline environments. Alk-CN also demonstrates versatility for H 2 O 2 production with other polyester-based plastics, including polybutylene terephthalate and polyla