Defect Engineering in CuS_x/COF Hybridized Heterostructures: Synergistic Facilitation of the Charge Migration for an Efficacious Photocatalytic Conversion of CO₂ into CO

Abstract

The photocatalytic CO2 reduction reaction (CO2RR) provides an attractive approach to tackling environmental issues. To actualize the optimal catalytic efficiency, one efficacious strategy is to rationally modulate the charge migration for the adopted heterogeneous catalysts. Herein, by virtue of a one-step hydrothermal method, Cu2S nanospheres and defect-rich Cu2S (CuS x ) nanosheets are wrapped by a triazine-containing covalent framework (TP-TA COF), resulting in CuS x /TP-TA and Cu2S/TP-TA. Owing to the heterojunction construction that suppresses the carrier recombination, both hybridized structures present enhanced charge migration in comparison to that of their corresponding sulfides and COF constituents. It is worth emphasizing that CuS x /TP-TA proffers a significantly greater photocurrent than Cu2S/TP-TA. The subsequent photocatalytic reduction of CO2 also exhibits an apparently higher CO evolution rate, about 2.8 times higher than the Cu2S/TP-TA photocatalyst. The above evident improvement owes much to the heterostructure establishment between CuS x and TP-TA COF, as well as the synergistic effect provided by the defect engineering for CuS x , both of which are able to enhance the separation efficiency of photoinduced carriers. Our work sheds light on the rational construction of heterogeneous structures between organic and inorganic photocatalysts, which emphasizes the possible synergistic effect of defect centers for enhancing photocatalytic performance.

Defects and Disorder in Covalent Organic Frameworks for Advanced Applications

“…Reproduced with permission. [165] Copyright 2022, American Chemical Society. thickness was reported.…”

“…In this context, one‐step hydrothermal method was employed to deposit Cu 2 S nanospheres and defect‐rich Cu 2 S (CuS x ) nanosheets on triazine‐containing COF material (TP‐TA COF) to obtain Cu 2 S/TP‐TA and CuS x /TP‐TA, respectively ( Figure ). [ 165 ] Interestingly, these two solids significantly suppress the charge carrier recombination due to the presence of heterojunction compared to their respective sulfides and COF constituents. Among these two solids, CuS x shows lower crystallinity and larger full width at half‐maxima, thus suggesting the existence of abundant defects.…”

Strategies for Enhancing the Photocatalytic and Electrocatalytic Efficiency of Covalent Triazine Frameworks for CO2 Reduction

“…Therefore, the hybrid systems of CTFs and inorganic semiconductor materials can improve photocatalytic reaction efficiency and selectivity. [81,[100][101][102][103][104] For example, Zhang et al [102] fabricated an inorganic/organic hybrid photocatalyst by the electrostatic self-assembly of Cs 2 AgBiBr 6 nanosheets (NSs) and CTF-1 NS. The CO 2 RR performance of the Cs 2 AgBiBr 6 /CTF-1(CABB/CTF-1) exhibited remarkable efficacy.…”

Site-Specified MOF/COF Heteronanosheets for Enhancing Photocatalytic CO2 Reduction

“…20 Meanwhile, two vibration signals appear at 1508 and 1365 cm −1 , which indicate the presence of a triazine ring in TTCOF. 21,22 In comparison to NZZ and TTCOF individually, the intensities of −NH 2 and HC�O groups in the NZZ 0.14 /TTCOF composite are evidently weakened. Conversely, the NZZ 0.14 / TTCOF composite possesses notably strengthened signals of C�C and C−N groups compared to NZZ and TTCOF.…”