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We demonstrate a new case of materials–gene engineering to precisely design photocatalysts with the prescribed properties. Based on theoretical calculations, a phase‐doping strategy was proposed to regulate the pathways of CO2 conversion over Au nanoparticles (NPs) loaded TiO2 photocatalysts. As a result, the thermodynamic bottleneck of CO2‐to‐CO conversion is successfully unlocked by the incorporation of stable twinning crystal planes into face‐centered cubic (fcc) phase Au NPs. Compared to bare pristine TiO2, the activity results showed that the loading of regular fcc‐Au NPs raised the CO production by 18‐fold but suppressed the selectivity from 84 % to 75 %, whereas Au NPs with twinning (110) and (100) facets boosted the activity by nearly 40‐fold and established near unity CO selectivity. This enhancement is shown to originate from a beneficial shift in the surface reactive site energetics arising at the twinned stacking fault, whereby both the CO reaction energy and desorption energy were significantly reduced. [ABSTRACT FROM AUTHOR]

D‐π‐A type 4‐((9‐phenylcarbazol‐3‐yl)ethynyl)‐N‐dodecyl‐1,8‐naphthalimide (CZNI) with a large dipole moment of 8.49 D and A‐π‐A type bis[(4,4′‐1,8‐naphthalimide)‐N‐dodecyl]ethyne (NINI) with a negligible dipole moment of 0.28 D, were smartly designed and synthesized to demonstrate the evidence of a molecular dipole as the dominant mechanism for controlling charge separation of organic semiconductors. In aqueous solution, these two novel naphthalimides can self‐assemble to form nanoribbons (NRs) that present significantly different traces of exciton dissociation dynamics. Upon photoexcitation of NINI‐NRs, no charge‐separated excitons (CSEs) are formed due to the large exciton binding energy, accordingly there is no hydrogen evolution. On the contrary, in the photoexcited CZNI‐NRs, the initial bound Frenkel excitons are dissociated to long‐lived CSEs after undergoing ultrafast charge transfer within ca. 1.25 ps and charge separation within less than 5.0 ps. Finally, these free electrons were injected into Pt co‐catalysts for reducing protons to H2 at a rate of ca. 417 μmol h−1 g−1, correspondingly an apparent quantum efficiency of ca. 1.3 % can be achieved at 400 nm. [ABSTRACT FROM AUTHOR]

Single‐atom metal‐insulator‐semiconductor (SMIS) heterojunctions based on Sn‐doped Fe2O3 nanorods (SF NRs) were designed by combining atomic deposition of an Al2O3 overlayer with chemical grafting of a RuOx hole‐collector for efficient CO2‐to‐syngas conversion. The RuOx‐Al2O3‐SF photoanode with a 3.0 nm thick Al2O3 overlayer gave a >5‐fold‐enhanced IPCE value of 52.0 % under 370 nm light irradiation at 1.2 V vs. Ag/AgCl, compared to the bare SF NRs. The dielectric field mediated the charge dynamics at the Al2O3/SF NRs interface. Accumulation of long‐lived holes on the surface of the SF NRs photoabsorber aids fast tunneling transfer of hot holes to single‐atom RuOx species, accelerating the O2‐evolving reaction kinetics. The maximal CO‐evolution rate of 265.3 mmol g−1 h−1 was achieved by integration of double SIMS‐3 photoanodes with a single‐atom Ni‐doped graphene CO2‐reduction‐catalyst cathode; an overall quantum efficiency of 5.7 % was recorded under 450 nm light irradiation. [ABSTRACT FROM AUTHOR]

The design and synthesis of two semiconducting bis (4‐ethynyl‐bridging 1, 8‐naphthalimide) bolaamphiphiles (BENI‐COO− and BENI‐NH3+) to fabricate supramolecular metal–insulator–semiconductor (MIS) nanostructures for biomimetic hydrogen evolution under visible light irradiation is presented. A H2 evolution rate of ca. 3.12 mmol g−1⋅h−1 and an apparent quantum efficiency (AQE) of ca. 1.63 % at 400 nm were achieved over the BENI‐COO−‐NH3+‐Ni MIS photosystem prepared by electrostatic self‐assembly of BENI‐COO− with the opposite‐charged DuBois‐Ni catalysts. The hot electrons of photoexcited BENI‐COO− nanofibers were tunneled to the molecular Ni collectors across a salt bridge and an alkyl region of 2.2–2.5 nm length at a rate of 6.10×108 s−1, which is five times larger than the BENI‐NH3+ nanoribbons (1.17×108 s−1). The electric field benefited significantly the electron tunneling dynamics and compensated the charge‐separated states insufficient in the BENI‐COO− nanofibers. [ABSTRACT FROM AUTHOR]

A metal–insulator–semiconductor (MIS) photosystem based on covalent organic framework (COF) semiconductors was designed for robust and efficient hydrogen evolution under visible‐light irradiation. A maximal H2 evolution rate of 8.42 mmol h−1 g−1 and a turnover frequency of 789.5 h−1 were achieved by using a MIS photosystem prepared by electrostatic self‐assembly of polyvinylpyrrolidone (PVP) insulator‐capped Pt nanoparticles (NPs) with the hydrophilic imine‐linked TP‐COFs having =C=O−H−N= hydrogen‐bonding groups. The hot π‐electrons in the photoexcited n‐type TP‐COF semiconductors can be efficiently extracted and tunneled to Pt NPs across an ultrathin PVP insulating layer to reduce protons to H2. Compared to the Schottky‐type counterparts, the COF‐based MIS photosystems give a 32‐fold‐enhanced carrier efficiency, attributed to the combined enhancement of photoexcitation rate, charge separation, and oxidation rate of holes accumulated in the valence band of the TP‐COF semiconductor. [ABSTRACT FROM AUTHOR]

An artificial photosynthetic (APS) system consisting of a photoanodic semiconductor that harvests solar photons to split H2O, a Ni‐SNG cathodic catalyst for the dark reaction of CO2 reduction in a CO2‐saturated NaHCO3 solution, and a proton‐conducting membrane enabled syngas production from CO2 and H2O with solar‐to‐syngas energy‐conversion efficiency of up to 13.6 %. The syngas CO/H2 ratio was tunable between 1:2 and 5:1. Integration of the APS system with photovoltaic cells led to an impressive overall quantum efficiency of 6.29 % for syngas production. The largest turnover frequency of 529.5 h−1 was recorded with a photoanodic N‐TiO2 nanorod array for highly stable CO production. The CO‐evolution rate reached a maximum of 154.9 mmol g−1 h−1 in the dark compartment of the APS cell. Scanning electrochemical–atomic force microscopy showed the localization of electrons on the single‐nickel‐atom sites of the Ni‐SNG catalyst, thus confirming that the multielectron reduction of CO2 to CO was kinetically favored. [ABSTRACT FROM AUTHOR]