Cocatalysts on Semiconductor Photocatalyst: A Mini Review

Keywords: cocatalyst, photocatalyst, semiconductor, solar energy conversion, water splitting


Recent progress in photocatalysts for sunlight energy conversion into chemical energy through water splitting, carbon dioxide (CO2) reduction, nitrogen fixation, etc. has witnessed the importance of cocatalysts in elevating the efficiency of the overall reaction systems. A cocatalyst can assist a semiconductor photocatalyst by promoting the transportation of photoexcited charges (electrons and holes). The improved shuttle of photoexcited charges has direct constructive impacts on the suppression of charge recombination, facilitation of redox reactions with reactants, and prevention of photo-corrosion (in certain photo-unstable semiconductor). Given the critical roles played by cocatalyst, the methodologies adopted in decorating such entities on a semiconductor photocatalyst would have influence in the surface and interfacial interaction between the two components, resulting in the tunability of reaction performance. In this mini review, we aim to summarize the structural configurations of cocatalyst-photocatalyst composites yielded via various loading methods. The implications of the resultant surface and interfacial interaction imposed by the cocatalysts are discussed to provide general guidance for tailoring an ideal photocatalytic system. Subsequently, we summarize the methodologies developed over years in loading of cocatalyst on semiconductor photocatalyst. The challenges presented at the end of this mini review serve as a platform of opportunity for this community to overcome or improve further.


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Author Biography

Yun Hau Ng, School of Energy and Environment, City University of Hong Kong, Hong Kong SAR, China

Foto_Prof YunHau_Ng.jpg

Yun Hau Ng is an associate professor in the School of Energy and Environment, City University of Hong Kong. He received his B.Sc. (Industrial Chemistry) from Universiti Teknologi Malaysia in 2003 and his Ph.D. from Osaka University in 2009. His research is focused on the development of novel photoactive semiconductors for sunlight energy conversion. He is awarded the Honda-Fujishima Prize in 2013 in recognition of his work in photo-driven water splitting. He received the Distinguished Lectureship Award from the Chemical Society of Japan in 2018 and APEC Science Prize for Innovation, Research and Education (ASPIRE) in 2019.


A. Fujishima and K. Honda, Electrochemical Photolysis of Water at a Semiconductor Electrode, Nature, 1971, 238, 37-38, DOI:

H. L. Tan, R. Amal, and Y. H. Ng, Alternate Strategies in Improving the Photocatalytic and Photoelectrochemical Activities of Visible Light-Driven BiVO4: A Review, J. Mater. Chem. A, 2017, 5, 16498-16521, DOI:

C. Y Toe, J. Scott, R. Amal, and Y. H. Ng, Recent Advances in Suppressing the Photocorrosion of Cuprous Oxide for Photocatalytic and Photoelectrochemical Energy Conversion, J. Photochem. Photobiol. C., 2019, 40, 191-211, DOI:

K. Fuku, T. Kamegawa, K. Mori, and H. Yamashita, Highly Dispersed Platinum Nanoparticles on TiO2 Prepared by using the Microwave-assisted Deposition Method: An Efficient Photocatalyst for the Formation of H2 and N2 from Aqueous NH3, Chem. Asian J., 2012, 7, 1366-1371, DOI:

T. H. Tan, R. J. Wong, J. Scott, Y. H. Ng, R. A. Taylor, K. –F. Aguey-Zinsou, and R. Amal, Multipronged Validation of Oxalate C-C Bond Cleavage Driven by Au-TiO2 Interfacial Charge Transfer using Operando DRIFTS, ACS Catal., 2012, 8, 715-7163, DOI:

F. Zhang, J. Chen, X. Zhang, W. Gao, R. Jin, N. Guan, and Y. Li, Synthesis of Titania-supported Platinum Catalyst: The Effect of pH on Morphology Control and Valence State During Photodeposition, Langmuir, 2004, 20, 9329-9334, DOI:

H. Song, X. Qiu, and F. Li, Effect of Heat Treatment on the Performance of TiO2-Pt/CNT Catalysts for Methanol Electro-Oxidation, Electrochim. Acta, 2008, 53, 3708-3713, DOI:

S. Chen, S. Shen, G. Liu, Y. Qi, F. Zhang, and C. Li, Interface Engineering of a CoOx/Ta3N5 Photocatalyst for Unprecedented Water Oxidation Performance under Visible-Light-Irradiation, Angew. Chem. Int. Ed., 2015, 54, 3047-3051, DOI:

I. V. Lightcap, T. H. Kosel, and P. V. Kamat, Anchoring Semiconductor and Metal Nanoparticles on a Two-Dimensional Catalyst mat. Storing and Shuttling Electrons with Reduced Graphene Oxide, Nano Lett., 2010, 10, 577-583, DOI:

O. Akhavan, M. Abdolahad, A. Esfandiar, and M. Mohatashamifar, Photodegradation of Graphene Oxide Sheets by TiO2 Nanoparticles after a Photocatalytic Reduction, J. Phys. Chem. C, 2010, 114, 12955-12959, DOI:

E. Cui, and G. Lu, Modulating Photogenerated Electron Transfer and Hydrogen Production Rate by Controlling Surface Potential Energy on a Selectively Exposed Pt Facet on Pt/TiO2 for Enhancing Hydrogen Production, J. Phys. Chem. C, 2013, 117, 26415-26425, DOI:

S. Bai, X. Wang, C. Hu, M. Xie, J. Jiang, and Y. Xiong, Two-Dimensional g-C3N4: An Ideal Platform for Examining Facet Selectivity of Metal Co-catalysts in Photocatalysis, Chem. Commun. 2014, 50, 609-6097, DOI:

S. Xie, Y. Wang, Q. Zhang, W. Fan, W., Deng, and Y. Wang, Photocatalytic Reduction of CO2 with H2O: Significant Enhancement of the Activity of Pt-TiO2 in CH4 Formation by Addition of MgO, Chem. Commun. 2013, 49, 2451-2453, DOI:

K. Czelej, K. Cwieka, J.C. Colmenares, and K. J. Kurzydlowski, Y.-J. Xu, Toward a Comprehensive Understanding of Enhanced Photocatalytic Activity of the Bimetallic PdAu/TiO2 Catalyst for Selective Oxidation of Methanol to Methyl Formate, ACS Appl. Mater. Interfaces, 2017, 9, 31825-31833, DOI:

K. Maeda, K. Teramura, D. Lu, N. Saito, Y. Inoue, and K. Domen, Noble-metal/Cr2O3 Core/shell Nanoparticles as a Cocatalyst for Photocatalytic Overall Water Splitting, Angew. Chem. Int. Ed., 2006, 45, 7806-7809, DOI:

R. Li, F. Zhang, D. Wang, J. Yang, M. Li, J. Zhu, X. Zhou, H. Han, and C. Li, Spatial Separation of Photogenerated Electrons and Holes among {010} and {110} Crystal Facets of BiVO4, Nat. Commun. 2013, 4, 1432, DOI:

X. Wu, J. N. Hart, X. Wen, L. Wang, Y. Du, S. X. Dou, Y. H. Ng, R. Amal, and J. Scott, Improving the Photo-oxidative Performance of Bi2MoO6 by Harnessing the Synergy Between Spatial Charge Separation and Rational Co-catalyst Deposition, ACS Appl. Mater. Interfaces, 2018, 10, 9342-9352, DOI:

T. Ohno, K. Sarukawa, and M. Matsumura, Crystal Faces of Rutile and Anatase TiO2 Particles and their Roles in Photocatalytic Reactions, New J. Chem., 2002, 26, 1167-1170, DOI:

P. Reineck, Y. Lin, B.C. Gibson, M. D. Dickey, A. D. Greentree, and I. S. Maksymov, UV Plasmonic Properties of Colloidal Liquid-Metal Eutectic Gallium-Indium Alloy Nanoparticles, Sci. Rep., 2019, 9, 5345, DOI:

H. M. Ngo, N. D. Lai, and I. Ledoux-Rak, High Second-order Nonlinear Response of Platinum Nanoflowers: The Role of Surface Corrugation, Nanoscale, 2016, 8, 3489-3495, DOI:

X. Zhang, F. Han, B. Shi, S. Farsinezhad, G. P. Dechaine, and K. Shankar, Photocatalytic Conversion of Diluted CO2 into Light Hydrocarbons using Periodically Modulated Multiwalled Nanotube Arrays, Angew. Chem. Int. Ed., 2012, 51, 12732-12735, DOI:

S. Xie, Y. Wang, Q. Zhang, W. Deng, and Y. Wang, MgO- and Pt-promoted TiO2 as an Efficient Photocatalyst for the Preferential Reduction of Carbon Dioxide in the Presence of Water, ACS Catal., 2014, 3644-3653, DOI:

P. D. Tran, L. F. Xi, S. K. Batabyal, L. H. Wong, J. Barber, and J. S. C. Loo, Enhancing the Photocatalytic Efficiency of TiO2 Nanopowders for H2 Production by using Non-noble Transition Metal Co-catalysts, Phys. Chem. Chem. Phys., 2012, 14, 11596-11599, DOI:

I. Rossetti, A. Villa, M. Compagnoni, L. Prati, G. Ramis, C. Pirola, C. L. Bianchi, W. Wang, and D. Wang, CO2 Photoconversion to Fuels under High Pressure: Effect of TiO2 Phase and of Unconventional Reaction Conditions, Catal. Sci. Technol., 2015, 5, 4481-4487, DOI:

F. Solymosi, and I. Tombacz, Photocatalytic Reaction of H2O + CO2 Over Pure and Doped Rh/TiO2, Catal. Lett., 1994, 27, 61-65, DOI:

H. Y. Lin, H. C. Yang, and W. L. Wang, Synthesis of Mesoporous Nb2O5 Photocatalysts with Pt, Au, Cu, and NiO Cocatalyst for Water Splitting, Catal. Today, 2011, 174, 106-113, DOI:

X. Feng, J. D. Sloppy, T. J. LaTempa, M. Paulose, S. Komarneni, N. Bao, and C. A. Grimes, Synthesis and Deposition of Ultrafine Pt Nanoparticles within High Aspect Ratio TiO2 Nanotube Arrays: Application to the Photocatalytic Reduction of Carbon Dioxide, J. Mater. Chem., 2011, 21, 13429-13433, DOI:

L. C. Liu, Z. Y. Li, W. X. Zou, X. R. Gu, Y. Deng, F. Gao, C. J. Tang, and L. Dong, In situ Loading Transition Metal Oxide Clusters on TiO2 Nanosheets as Co-catalysts for Exceptional High Photoactivity, ACS Catal., 2013, 3, 2052-2061, DOI:

Q. Kang, T. Wang, P. Li, L. Liu, K. Chang, M. Li, J. Ye, Photocatalytic reduction of carbon dioxide by hydrous hydrazine over Au-Cu alloy nanoparticles supported on SrTiO3/TiO2 coaxial nanotube arrays, Angew. Chem. Int. Ed., 2015, 54, 841-845. DOI:

E. Liu, L. Qi, J. Bian, Y. Chen, X. Hu, J. Fan, H. Liu, H., C. Zhu, and Q. Wang, A Facile Strategy to Fabricate Plasmonic Cu Modified TiO2 Nanoflower Films for Photocatalytic Reduction of CO2 to Methanol, Mater. Res. Bull., 2015, 68, 203-209, DOI:

S. Zhang, B. Peng, S. Yang, H. Wang, H. Yu, Y. Fang, and F. Peng, Non-noble Metal Copper Nanoparticles-Decorated TiO2 Nanotube Arrays with Plasmon-Enhanced Photocatalytic Hydrogen Evolution under Visible Light, Int. J. Hydrogen Energy, 2015, 40, 303-310, DOI:

K. S. Raja, Y. R. Smith, N. Kondamudi, A. Manivannan, M. Misra, and V. R. Subramanian, CO2 Photoreduction in the Liquid Phase over Pd-Supported on TiO2 Nanotube and Bismuth Titanate Photocatalysts, Electrochem. Solid-State Lett., 2011, 14, F5-F8, DOI:

Z. Zhang, Z. Wang, S.-W. Cao, and C. Xue, Au/Pt Nanoparticle-decorated TiO2 Nanofibers with Plasmon-enhanced Photocatalytic Activities for Solar-to-fuel Conversion, J. Phys. Chem. C, 2013, 117, 25939-25947, DOI:

W.-N. Wang, W.-J. An, B. Ramalingam, S. Mukherjee, D. M. Niedzwiedzki, S. Gangopadhyay, and P. Biswas, Size and Structure Matter: Enhanced CO2 Photoreduction Efficiency by Size-resolved Ultrafine Pt Nanoparticles on TiO2 Single Crystals, J. Am. Chem. Soc., 2012, 134, 11276-11281, DOI:

C. Zhao, A. Krall, H. Zhao, Q. Zhang, and Y. Li, Ultrasonic Spray Pyrolysis Synthesis of Ag/TiO2 Nanocomposite Photocatalysts for Simultaneous H2 Production and CO2 Reduction. Int. J. Hydrogen Energy, 2012, 37, 9967-9976, DOI:

K. Hirano, K., Inoue, and T. Yatsu, Photocatalysed Reduction of CO2 in Aqueous TiO2 Suspension Mixed with Copper Powder, J. Photochem. Photobiol. A, 1992, 64, 255-258, DOI: 10.1016/1010-6030(92)85112-8.

K. Wenderich, and G. Mul, Methods, Mechanism, and Applications of Photodeposition in Photocatalysis: A Review, Chem. Rev., 2016, 116, 14587-14619, DOI:

Cocatalyst is a crucial component to provide efficient photocatalytic system. It serves different functions, ranging from electron sinks for the excited photocatalyst to the passivation role to suppress photo-corrosion of photocatalyst. The methods in loading cocatalyst onto semiconductor photocatalysts can affect the extent of influence. This minireview is, therefore, summarizing the commonly used and newly developed techniques in decorating photocatalyst with cocatalyst.
How to Cite
Ng, Y. H. (2019). Cocatalysts on Semiconductor Photocatalyst: A Mini Review. Journal of the Indonesian Chemical Society, 2(2), 72.