Unleashing Insulating Polymer as Charge Transport Cascade Mediator

Abstract

Crafting spatially controllable charge transfer channels at the nanoscale level remains an enduring challenge in solar-to-chemical conversion technology. Despite the advancements, it still suffers from sluggish interfacial charge transport kinetics and scarcity of strategies to finely modulate charge transport pathways. Herein, this article demonstrates the unexpected charge modulation property of non-conjugated insulating polymer assisted by a universal layer-by-layer self-assembly tactic. Oppositely charged poly(dimethyl diallyl ammonium chloride) (PDDA) and Ti 3 C 2 MXene quantum dots (MQDs) are periodically attached to the wide bandgap metal oxides (WMOs) to design multilayered heterostructured photoanodes. The intermediate PDDA layer acts as an efficacious charge relay medium to access directional electron flow from WMOs to Ti 3 C 2 MQDs, while Ti 3 C 2 MQDs serve as the electron extractor. Charge transfer cascade is thus stimulated on account of the simultaneous electron-trapping capabilities of interim PDDA layer and Ti 3 C 2 MQDs, which synergistically favors the conspicuously boosted charge separation over WMOs, affording the WMOs/(PDDA/MQDs) n photoanodes with considerably enhanced photoelectrochemical (PEC) water oxidation performances. Moreover, PEC performances of such photoanodes can be tuned by interface configuration via assembly number and sequence. This work will provide an insightful perspective to craft a directional charge transfer pathway through insulating polymer for solar energy conversion.

Charge modulation over atomically precise metal nanoclusters via non-conjugated polymers for photoelectrochemical water oxidation

“…3d, T(Au x P) 8 exhibits the smallest semicircle arc radius compared with T(Ag x P) 8 , T(Au 25 P) 8 , TP 8 , and TNTAs, implying its most efficient interfacial charge separation efficiency. 21,49 As summarized in Table S3, † T(Au x P) 8 demonstrates the lowest charge transfer resistance (3290 U) with respect to other photoelectrodes, that is, T(Ag x P) 8 (3375 U), T(Au 25 P) 8 (4233 U), TP 8 (11 170 U), and TNTAs (11 510 U), implying that cooperativity of Au x NCs and PAH is advantageous to boost the interfacial charge transport efficiency. The results are consistent with the LSV and I-t results.…”

“…[18][19][20] Consequently, in previous studies, high-temperature calcination is essentially compulsory to remove the non-conjugated insulating polymer in fabricating non-conjugated polymer-involved optoelectronic devices so as to reduce the interfacial charge transport resistance. 21,22 This leads us to consider what the positive role of nonconjugated insulating polymers can play in boosting interfacial charge migration. Inspired by the electron tunneling capability of conventional semiconductor-insulator-metal photosystems, wherein insulating metal oxides (e.g., SiO 2 & Al 2 O 3 ) are generally harnessed as the intermediate layers to stimulate the electron tunneling, we speculate that non-conjugated insulating polymers might also play the analogous tunneling role to participate in the charge modulation.…”

Unexpected Insulating Polymer Maneuvered Solar CO2‐to‐Syngas Conversion

“…Highresolution Cl 2p spectrum of CP 7 (Figure 1hII) exhibits two bands at 198.7 eV (Cl 2p 3/2 ) and 200.5 eV (Cl 2p 1/2 ) that cor respond to the Cl − species from PDDA ingredient. [24,25] Thus, the result evidences the successful PDDA encapsulation on the CIS NSs substrate. Highresolution Fe 2p spectrum of CP 7 F 7 fails to show an apparent signal due to the low deposition con tent (Figure S5c, Supporting Information), but a clear nickel signal is detected in the Ni 2p spectrum of CP 7 F 7 , wherein the representative Ni 2p spectrum shows two major peaks at 855.4 and 873.1 eV caused by Ni 2p 3/2 of αNi(OH) 2 , together with satellite bands at 860.6 and 880.0 eV (Figure 1i).…”

“…of Cd 3d, In 3d, and S 2p peaks of CP are concurrently blueshifted toward lower value (≈0.2-0.35 eV), implying the change of surface electron density as a result of PDDA encapsulation. Alternatively, high resolution N 1s and Cl 2p spectra of CP 7 F 7 are exhibited in Figure 1hIII and Figure S5b (Supporting Information), wherein the bands at ≈399 and 402 eV correspond to the NH 2 /NH and NH 4 + functional groups from PDDA layer, [24] respectively. Highresolution Cl 2p spectrum of CP 7 (Figure 1hII) exhibits two bands at 198.7 eV (Cl 2p 3/2 ) and 200.5 eV (Cl 2p 1/2 ) that cor respond to the Cl − species from PDDA ingredient.…”

Atomically precise thiolate-protected gold nanoclusters: current advances in solar-powered photoredox catalysis

“…Overall, we have summarized the latest developments in the growth mechanism and classication of gold NCs, and the photocatalytic mechanism of gold NC-based photosystems along with multiple photocatalytic applications including nonselective dye degradation, selective organic transformation, photocatalytic water splitting, photocatalytic CO 2 reduction and PEC water splitting. Although the progress on metal NCs and photocatalysis as well as photoelectrocatalysis is encouraging, [122][123][124][125][126][127][128][129][130][131][132][133][134][135][136][137][138][139] solar-driven gold NC-based photocatalysts are still a new research eld lacking in-depth study, and moreover, its photocatalytic applications are limited with solar energy conversion efficiency being far from satisfactory. From our perspective, the following several challenges should be highlighted in future research work.…”