Construction of Carbon Dot-Modified g-C₃N₄/BiOIO₃ Z-Scheme Heterojunction for Boosting Photocatalytic CO₂ Reduction under Full Spectrum Light

Abstract

In this study, we successfully constructed a Zscheme BiOIO 3 /CQDs/g-C 3 N 4 (BCCN) composite modified with carbon quantum dots (CQDs) for photocatalytic CO 2 reduction. A series of characterization approaches and testing technologies were carried out to investigate the components, morphologies, and optical properties of the fabricated photocatalysts. The 0.015B0.01CCN displayed an efficient photocatalytic CO 2 reduction activity within 7 h full spectrum light irradiation, producing CO with a rate of 117.88 μmol g cat −1. The enhanced photocatalytic CO 2 reduction of the BCCN composite can be attributed to the synergistic effects of CQDs and the Zscheme heterojunction. This work presents a new insight into integrating CQDs with g-C 3 N 4 and BiOIO 3 for the positive synergetic effect to obtain a high-efficient photocatalyst.

Constructing Defective Heterojunctions of BiOBr Nanosheets and Hollow NH2‐functionalized MOFs for Visible‐light‐driven CO2 Reduction with Nearly 100% CO Selectivity by Pure H2O

“…For Z‐scheme heterojunction, the electrons on CB of NH 2 ‐MIL‐125(Ti) moved to VB of BiOBr and recombined with hole under the action of built‐in electric field. Owing to the CB potential of NH 2 ‐MIL‐125(Ti) is lower than CO 2 /CO reduction potential (‐0.53 V vs NHE), CO cannot produce in the type II heterojunction [32] . By contrast, the electrons on BiOBr and the holes on the NH 2 ‐MIL‐125(Ti) remain motionless, thus achieving the efficient spatial separation of the photogenerated electron‐hole pairs in the Z‐scheme heterojunction.…”

“…Owing to the CB potential of NH 2 -MIL-125(Ti) is lower than CO 2 / CO reduction potential (-0.53 V vs NHE), CO cannot produce in the type II heterojunction. [32] By contrast, the electrons on BiOBr and the holes on the NH 2 -MIL-125(Ti) remain motionless, thus achieving the efficient spatial separation of the photogenerated electron-hole pairs in the Z-scheme heterojunction. Simultaneously, the band of BiOBr (-2.59 V) can meet the potential demand of CO 2 reduction to CO.…”

Converting CO2 into Value‐Added Products by Cu2O‐Based Catalysts: From Photocatalysis, Electrocatalysis to Photoelectrocatalysis

“…[10] In particular, the O and C atoms in the CO 2 molecule can act as electron donors and acceptors to form a mixed coordination structure with the catalyst (Figure 2c). [10] Then, CO 2 can be converted into a series of value-added products, such as carbon monoxide (CO), [59][60][61][62][63] formic acid (HCOOH), [64] formaldehyde (CH 2 O), methanol (CH 3 OH), [65][66][67] methane (CH 4 ), [68][69][70][71] ethylene (CH 2 CH 2 ) [72][73][74][75] and ethanol (CH 3 CH 2 OH), [76][77][78][79] through reduction reactions involving 2e − , 4e − , 6e − , 8e − or more electrons. The thermodynamic potentials corresponding to different CO 2 reduction products are listed in Table 1 when the pH of the aqueous solution is 7, the temperature is 25 °C, and the pressure is 1 atm.…”

Progress and Outlook of Surface Engineering Strategies in Photocatalytic Materials for Mercury Removal: A Review

“…In addition, constructing heterogeneous structures to increase the interfacial electron transfer rate is also an effective way to promote the photocatalytic reduction of CO 2 . Hu et al 134 successfully constructed carbon dot-modified g-C 3 N 4 / BiOIO 3 heterojunctions with Z-type electron transfer with an overall yield of 117.88 μmol/g cat in the full spectrum, mainly due to the Z-type heterojunctions promoting the migration and separation of photogenerated charges. Wang et al 135 synthesized CuInS 2 /g-C 3 N 4 photocatalysts with bimetallic sites, and the photocatalytic CO yield was 246.75 μmol•g −1 • h −1 with selectivity greater than 93%.…”