Atomically Dispersed Janus Nickel Sites on Red Phosphorus for Photocatalytic Overall Water Splitting

Abstract

Single-atom nickel catalysts hold great promise for photocatalytic water splitting due to their plentiful active sites and cost-effectiveness. Herein, we adopt a reactive-group guided strategy to prepare atomically dispersed nickel catalysts on red phosphorus. The hydrothermal treatment of red phosphorus leads to the formation of PÀ H and PÀ OH groups, which behave as the reactive functionalities to generate the dual structure of single-atom PÀ Ni and PÀ OÀ Ni catalytic sites. The produced single-atom sites provide two different functions: PÀ Ni for water reduction and PÀ OÀ Ni for water oxidation. Benefitting from this specific Janus structure, Ni-red phosphorus shows an elevated hydrogen evolution rate compared to Ni nanoparticle-modified red phosphorus under visible-light irradiation. The hydrogen evolution rate was additionally enhanced with increased reaction temperature, reaching 91.51 μmol h À 1 at 70 °C, corresponding to an apparent quantum efficiency of 8.9 % at 420 nm excitation wavelength.

Boosting Photocatalytic Hydrogen Peroxide Production from Oxygen and Water Using a Hafnium-Based Metal–Organic Framework with Missing-Linker Defects and Nickel Single Atoms

“…Hf-0.5 produced mainly O 2 , whereas Ni/Hf-0.5 demonstrated high selectivity (86%) for H 2 O 2 production by water oxidation. The Ni single atoms showed high H 2 O 2 selectivity in the water oxidation process presumably because H 2 O 2 is likely to form on Ni single atoms as a result of −OH species remaining on the Ni single atoms after water cleavage. , Thus, Ni single atoms deposited onto Hf-0.5 promoted not only charge separation but also selective two-electron water oxidation to produce H 2 O 2 , which led to a substantial increase in H 2 O 2 production.…”

“…This result suggests that photogenerated holes can migrate to Ni single atoms. Therefore, a Ni single atom presumably contributes to water oxidation as a cocatalyst. , …”

“…Therefore, a Ni single atom presumably contributes to water oxidation as a cocatalyst. 9,48 To clarify the H 2 O 2 production pathway during photocatalysis, we conducted active-species quenching tests using scavengers. Different free-radical scavengers (i.e., p-BQ for O 2…”

Atomically Dispersed Au-Assisted C–C Coupling on Red Phosphorus for CO2 Photoreduction to C2H6

“…In 2021, it was found to exhibit activity in photocatalytic CO 2 reduction . In our opinion, RP has several advantages: (i) RP has a single constituent element, which can provide a uniform coordination environment for metal single atoms. − (ii) In addition, compared with common single-atom coordination elements (N, O, S, etc. ), phosphorus (P) has lower electronegativity, so the coordination of P elements can control the electron density of a metal single atom. , (iii) More importantly, the electron-rich P atoms can effectively adsorb CO 2 and interact with O in CO 2 through Lewis acid–base interactions, which could boost the cleavage of C–O bonds and then produce large C 1 intermediates.…”

Continuous Charge Transport in Carbon Nitride Modulated by Interfacial Chemical Bond and Homophase Junction to Boost Photocatalytic Hydrogen Production

“…The demand for green energy sources has generated a strong desire for the production of clean and renewable energy [1–4] . Hydrogen energy is one of the most promising alternatives to the fossil fuels because of its high energy density and water as the only by‐product [5] . Among various approaches access to hydrogen sources, photocatalytic hydrogen production via water splitting has been considered as one of environment‐friendly and effective strategies by utilizing sunlight and water [6,7] .…”