Hydrochar-Supported NiFe₂O₄Nanosheets with a Tailored Microstructure for Enhanced CO₂Photoreduction to Syngas

Abstract

Constructing high-efficiency composite photocatalysts with enhanced charge transfer and a rapid surface catalytic reaction has recently received significant attention. Herein, a hydrochar-mediated NiFe 2 O 4 nanosheet (C/NFO) composite was rationally constructed by a simple hydrothermal method. Intimate interface contacts and chemical interactions between hydrochar and NFO were formed. The prepared C/NFO samples exhibited remarkable visible-light-driven catalytic CO 2 reduction properties under mild reaction conditions with Ru(bpy) 3 2+ sensitization. As the optimized sample, 16%-C/NFO achieved a 4-fold enhancement of CO production (17.49 μmol/h) compared with that of pure NFO. The C/NFO samples demonstrated good activity and structural stability in the CO 2 photoreduction system. The carbon source of CO derived from CO 2 was verified through isotopic labeling experiments using 13 CO 2 . In situ photoluminescence and electrochemical characterizations confirmed the role of electron transfer intermediates of C/NFO. The synergistic effect of the nanosheet-like structure of NFO, combined with the surface functional groups of hydrochar, facilitated an exceptionally high rate of charge transfer and exposed abundant active adsorption sites for CO 2 , thereby promoting the efficient separation of photogenerated charge carriers and enhancing photocatalytic activity for CO 2 reduction. This study presents a promising strategy for the rational design of hydrochar coupled with transition metal compound catalysts for efficient CO 2 photoreduction.

In Situ Construction of CuTCPP/Bi4O5Br2 Hybrids for Improved Photocatalytic CO2 and Cr(VI) Reduction

“…The photocurrent response and electrochemical impedance spectra were utilized to examine the photogenerated electron–hole migration capacity. As shown in Figure a, the transient photocurrent response of CuTCPP/Bi 4 O 5 Br 2 -2 is much higher than that of Bi 4 O 5 Br 2 , indicating that the introduction of CuTCPP is more beneficial to promote photogenerated carrier separation . Meanwhile, the semicircular diameter in electrochemical impedance spectroscopy spectra of CuTCPP/Bi 4 O 5 Br 2 -2 is smaller than that of Bi 4 O 5 Br 2 (Figure b), which indicates that CuTCPP/Bi 4 O 5 Br 2 -2 has a smaller transfer resistance and more favorable charge migration rate .…”

Tailoring Charge Separation in ZnIn2S4@CdS Hollow Nanocages for Simultaneous Alcohol Oxidation and CO2 Reduction under Visible Light

“…Artificial photosynthesis via coupling photocatalytic reduction of CO 2 with oxidation of H 2 O is a promising technology that can be used to convert solar energy into usable fuels and fine chemicals in a sustainable way . It attracts broad research interest and has been demonstrated as a potential strategy to address energy crisis and environment problems. − Up to date, various kinds of catalysts such as metal–organic frameworks (MOFs), − metallic oxides, , metallic sulfides, , covalent organic frameworks (COFs), , and compounds , are developed to drive multielectron CO 2 reduction. However, the sluggish oxidation reaction (2H 2 O + 4h + → 4H + + O 2 ) triggered by photoexcited holes (h + ) greatly limited the photocatalytic activity of these photocatalysts. − Although sacrificial reagents can help to improve CO 2 reduction activity, the expenses should not be overlooked such as cost-push, whole energy dissipation, secondary pollution, etc .…”

Boosting the Photocatalytic Performance of g-C3N4 through MoS2 Nanotubes with the Cavity Enhancement Effect

“…Simultaneously, the identification of a low-energy consumption method for treating industrial pollutants is of paramount importance. The advent of photocatalysis has not only initiated innovative research directions but has also played a crucial role in this transformative journey. − Since 1972, the groundbreaking research led by Fujishima and collaborators, utilizing TiO 2 as a photocatalyst for water separation, has instigated a continuous, collaborative global effort spanning over five decades. The prolonged commitment of researchers worldwide has propelled photocatalysis into an advanced, cost-efficient, and highly effective technology .…”