Synergistic Functionality of Dopants and Defects in Co‐Phthalocyanine/B‐CN Z‐Scheme Photocatalysts for Promoting Photocatalytic CO₂ Reduction Reactions

Abstract

The realization of solar‐light‐driven CO2 reduction reactions (CO2 RR) is essential for the commercial development of renewable energy modules and the reduction of global CO2 emissions. Combining experimental measurements and theoretical calculations, to introduce boron dopants and nitrogen defects in graphitic carbon nitride (g‐C3N4), sodium borohydride is simply calcined with the mixture of g‐C3N4 (CN), followed by the introduction of ultrathin Co phthalocyanine through phosphate groups. By strengthening H‐bonding interactions, the resultant CoPc/P‐BNDCN nanocomposite showed excellent photocatalytic CO2 reduction activity, releasing 197.76 and 130.32 µmol h−1 g−1 CO and CH4, respectively, and conveying an unprecedented 10‐26‐time improvement under visible‐light irradiation. The substantial tuning is performed towards the conduction and valance band locations by B‐dopants and N‐defects to modulate the band structure for significantly accelerated CO2 RR. Through the use of ultrathin metal phthalocyanine assemblies that have a lot of single‐atom sites, this work demonstrates a sustainable approach for achieving effective photocatalytic CO2 activation. More importantly, the excellent photoactivity is attributed to the fast charge separation via Z‐scheme transfer mechanism formed by the universally facile strategy of dimension‐matched ultrathin (≈4 nm) metal phthalocyanine‐assisted nanocomposites.

RETRACTED: Engineering MPC-Assisted Heterojunctional Photo-Oxidation Tailored by Interfacial Design of a P-Modulated C3N4 Heterojunction for Improved Aerobic Alcohol Oxidation

“…This heterostructure is distinguished by a unique EPR signal at a g -value of 2.049, which is associated with Cu 2+ ions (3d 9 ) within CuPc. Intriguingly, this Cu 2+ signal decreases under 405 nm light exposure, providing definitive evidence of electron transfer from the ligand to Cu 2+ , resulting in the partial reduction of Cu 2+ to a lower valence state of Cu + (3d 10 ), which does not exhibit an EPR signal . EPR spectra for both CuPc and the 4Cu/9P-BCN heterostructure were obtained under 660 nm light exposure, as shown in Figures S16b and i Supporting Information, respectively.…”

“…Intriguingly, this Cu 2+ signal decreases under 405 nm light exposure, providing definitive evidence of electron transfer from the ligand to Cu 2+ , resulting in the partial reduction of Cu 2+ to a lower valence state of Cu + (3d 10 ), which does not exhibit an EPR signal. 25 EPR spectra for both CuPc and the 4Cu/9P-BCN heterostructure were obtained under 660 nm light exposure, as shown in Figures S16b and 6i Supporting Information, respectively. The observed rise in signal that is ascribed to delocalized electrons in BCN suggests that photogenerated electrons in CuPc are moving to BCN.…”

“…Prior research has emphasized that specific dopants play a diverse role within the host materials, with larger dopants usually occupying interstitial spaces and highly electronegative dopants influencing electron donor levels near the conduction band, whereas less electronegative dopants affect electron acceptor states near the valence band. The introduction of heteroatom dopants can also induce spin density asymmetry, potentially enhancing molecular attraction through spin polarization. , …”

“…The introduction of heteroatom dopants can also induce spin density asymmetry, potentially enhancing molecular attraction through spin polarization. 24,25 Recent investigations have revealed that semiconductors such as BiVO 4 , Fe 2 O 3 , etc. present considerable potential to form optimal organic−inorganic hybrids with CN, attributed to their profound valence bands and staggered energy band configurations.…”

Charge transfer in TiO2-based photocatalysis: fundamental mechanisms to material strategies

“…206 Accordingly, the inactive photoexcited electrons and holes are removed through their recombination, leaving functional photoexcited electrons and holes with the highest thermodynamic energy to perform accelerated redox reactions. 172,207,208…”