Surface functionalization of soft photocathodes with an azido-phosphonic acid monolayer for robust and efficient solar-to-H2 conversion
10 affiliations
- 1School of Materials Sciences and Engineering
- 2Georgia Institute of Technology
- 3Department of Chemistry
- 4University of Pennsylvania
- 5RASEI
- 6University of Colorado Boulder
- 7Department of Chemistry and Biochemistry
- 8University of Arizona
- 9Department of Chemical and Biochemical Engineering
- 10School of Chemistry and Biochemistry
Abstract
Organic semiconductors are promising candidates for light-assisted electrocatalysis but interfacial design remains a key challenge for improving performance and durability. Design guidelines include: i) appropriate matching of the catalyst Fermi level to the transport level of charges in the organic semiconductor under operando; ii) controlling surface hydrophilicity for rapid bubble-release in the hydrogen evolution reaction; and iii) retained operation in acidic and alkaline media. Herein we demonstrate a surface-modification approach on five different soft photocathodes to create terminating phosphonic acid surfaces, yielding high-surface energy interfaces across pH ranges from 1 to 13. In acidic conditions, using Pt nanoparticle catalysts, photoelectrochemical devices exhibit photocurrent densities of ~9 mA cm−2 and onset potential of ~0.82 V, surpassing non-surface modified controls by approximately 35–95% and 10–30%, respectively. Improvements are attributed to efficient gas bubble desorption kinetics and increased photovoltages. Surface-enhanced Raman spectroscopy is then used to monitor the Stark shift of a vibrational probe molecule on a metal nanoparticle, enabling the quantification of the quasi-Fermi level of the catalytic site and photovoltage on the unmodified and modified polymer surfaces under operation (i.e., applied bias). The phosphonic acidterminated surfaces yield dramatically increased photovoltages relative to unmodified surfaces. Finally, to demonstrate the broader application of the modifier, we show the approach is readily amenable to increasing the pH~6 for Pt and the binding stability RuOx catalysts. Collectively, our observations suggest a scalable, robust, and efficient route to organic photoelectrochemical devices as well as energy conversion and storage and sensing platforms.
Related
- Metal-free CO2 fixation: conversion of epoxides to cyclic carbonates by a highly efficient bifunctional boron-tethered N-heterocyclic nitrenium catalyst
- Bimetallic Bi–In interfaces on micropyramidal silicon for efficient solar-driven CO 2 -to-formate conversion
- Atomic Efficient Synthesis of 1,2,4-Butanetriol: Catalysts, Conversion Routes and Reaction Mechanism
- A Hydrogen-Bonding Phosphonium/HFIP Catalyst for Efficient CO2 Conversion into Cyclic Carbonates
- Zeolite membrane reactors for efficient catalytic conversion of CO2 into high-value chemicals
BibTeX
@misc{suh2026surface,
title = {{Surface functionalization of soft photocathodes with an azido-phosphonic acid monolayer for robust and efficient solar-to-H2 conversion}},
author = {Eui Hyun Suh and Bo Dong and Yadong Zhang and Zhiting Chen and Giorgi Petriashvili and Stephen Barlow and Tianquan Lian and Seth R. Marder and Erin L. Ratcliff},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15009763/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009763/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Surface functionalization of soft photocathodes with an azido-phosphonic acid monolayer for robust and efficient solar-to-H2 conversion
AU - Eui Hyun Suh
AU - Bo Dong
AU - Yadong Zhang
AU - Zhiting Chen
AU - Giorgi Petriashvili
AU - Stephen Barlow
AU - Tianquan Lian
AU - Seth R. Marder
AU - Erin L. Ratcliff
PY - 2026
DA - 2026/10/01
PB - ChemRxiv
DO - 10.26434/chemrxiv.15009763/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009763/v1
AB - Organic semiconductors are promising candidates for light-assisted electrocatalysis but interfacial design remains a key challenge for improving performance and durability. Design guidelines include: i) appropriate matching of the catalyst Fermi level to the transport level of charges in the organic semiconductor under operando; ii) controlling surface hydrophilicity for rapid bubble-release in the hydrogen evolution reaction; and iii) retained operation in acidic and alkaline media. Herein we demonstrate a surface-modification approach on five different soft photocathodes to create terminating phosphonic acid surfaces, yielding high-surface energy interfaces across pH ranges from 1 to 13. In acidic conditions, using Pt nanoparticle catalysts, photoelectrochemical devices exhibit photocurrent densities of ~9 mA cm−2 and onset potential of ~0.82 V, surpassing non-surface modified controls by approximately 35–95% and 10–30%, respectively. Improvements are attributed to efficient gas bubble desorption kinetics and increased photovoltages. Surface-enhanced Raman spectroscopy is then used to monitor the Stark shift of a vibrational probe molecule on a metal nanoparticle, enabling the quantification of the quasi-Fermi level of the catalytic site and photovoltage on the unmodified and modified polymer surfaces under operation (i.e., applied bias). The phosphonic acidterminated surfaces yield dramatically increased photovoltages relative to unmodified surfaces. Finally, to demonstrate the broader application of the modifier, we show the approach is readily amenable to increasing the pH~6 for Pt and the binding stability RuOx catalysts. Collectively, our observations suggest a scalable, robust, and efficient route to organic photoelectrochemical devices as well as energy conversion and storage and sensing platforms.
ER -