Supporting Information. Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad, India

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1 Supporting Information Hierarchical Porous TiO 2 Embedded Unsymmetrical Zn-Phthalocyanine Sensitizer for Visible Light Induced Photocatalytic H 2 Production Authors: Amritanjali Tiwari, Narra Vamsi Krishna, L. Giribabu,* Ujjwal Pal* Academy of Scientific and Innovative Research (AcSIR), New Delhi, India Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Hyderabad, India Structural characterization Powder X-ray diffraction patterns (XRD) of the photocatalysts were recorded on a Bruker AXS diffractometer (D8 advance) at a generator voltage of 40 kv and current 30 ma using Cu-Kα radiation (λ = Å). The sample was scanned in the range of 2θ = with the scan rate 1 s/step. N 2 adsorption desorption isotherms of the photocatalysts were obtained on a Quantachrome Nova 2200e gas adsorption analyzer at 77 K. Field emission scanning electron microscopy (FESEM) was performed on a Carl Zeiss SIGMA HD field-emission scanning electron microscope. Transmission electron microscopy (TEM) image of the representative TNR sample was obtained by using a JEOL 2010EX TEM instrument equipped with the high-resolution style objective-lens pole piece at an acceleration voltage of 200 kv fitted with a CCD camera. Absorption spectra were recorded with a Shimadzu UV-3600, UV-visible-NIR. Fluorescence lifetime measurements were carried out using a ps timecorrelated single photon counting (TCSPC) setup (FluoroLog3-Triple Illuminator, IBH Horiba JobinYvon) employing a ps light emitting diode laser (NanoLED, ex = 670 nm) as excitation source. The decay curves were recorded by monitoring the fluorescence emission maxima of the phthalocyanine macrocycle ( em = 700 nm, the intensity was normalized). The photocatalytic experiments were carried out under external light source using a 300 W xenon arc lamp (Newport, USA). GC analysis was performed by gas chromatograph TCD detector 90 (Agilent 7890) using Argon as carrier gas. The conditions of XRD data collection are as given below: Scan Axis: Gonio Start Position ( 2θ): 5 Start Position ( 2θ): 95 Step Size ( 2θ): Anode material: Cu Generator setting: 40 ma, 40 kv S1

2 Apparent quantum yield (AQY) was measured under the same photoreaction conditions except that the incident monochromatic light under different band-pass filters has been used. The incident photon number was determined by optical power/energy meter (Newport, model: 842-PE), and the AQY value was estimated according to the given equations (1 & 2). 5 photons = P hc x t eqn (1) H 2 [%] = 2 x number of reacted electrons number of incident photons x 100 = 2 x Number of evolved H 2 molecule Number of incident photon x 100 eqn (2) TiO 2 (101) d-= nm Figure S1: TEM images of HPT-500 Figure S2: Cyclic ( ) and differential pulse voltammograms (------) of PCH001 a b Nafion layer Pt Pt TiO 2 d= nm TiO 2 (101) d= nm Pt (111) Figure S3: TEM images of Pt-HPT-500 S2

3 H 2 Yield ( mol) Figure S4: MALDI-TOF of PCH-001 dye HOMO ev LUMO ev HOMO LUMO ev ev Figure S5. Molecular orbital of the dye PCH01 calculated by DFT studies HPT-RT HPT-400 HPT-500 ctio Irradiation time/h Figure S6. Time course of the photocatalytic H 2 production curves over HPT-RT, HPT-400, HPT-500 and ctio 2 photocatalysts; Reaction conditions: 15 mg of each photocatalyst using 10 vol% TEOA aqueous medium at ph-7. S3

4 Table S1: Comparison of the photocatalytic efficiency for hydrogen production of various catalysts Photocatalyst Cocatalyst Light source a Reaction condition H 2 Rate Ref. Zn-tri-PcNc- g- Pt (1 wt %) λ 500 nm 10 mg 1.0 wt % Pt-loaded catalyst with 5.0 μmol g 1 Zn-tri-PcNc, 10 ml of water containing 50 mm AA, 10 vol % TEOA or10 mm EDTA μmol h 1 TON 5008 h 1 1 g- (LI-4/g /Zn-tri-PcNc) Pt (0.5 wt %) λ μmol h 1 TON 7428 h 1 2 LI-4/g- Pt (0.5 wt %) λ μmol h 1 2 Zn-tri-PcNc/g- Pt (0.5 wt%) λ μmol h 1 2 Zn-tri-PcNc-2- Pt/g- Zn-tetrad-Nc-Pt/g- Pt (0.5 wt%) λ 500 nm 1 g L 1 catalyst in 10 ml water containing 50 mm AA, 0.5 wt % Pt and 5 mmol g 1 dye Pt (0.5 wt%) λ 500 nm 1 g L 1 catalyst in 10 ml water containing 50 mm AA, 0.5 wt % Pt and 5 mmol g 1 dye 132 μmol h μmol h 1 3 Zn-di-PcNcTh-1- g- Pt (1 wt %) 500 W high pressure Hg-lamp 10 mg dye-sensitized 1wt% Pt/g- photocatalyst in 10 ml of 50 mm AA aqueous solution and dyeloading amount on Pt/g- is 5.0 μmol g μmol g 1 4 Zn-tetrad-Pc-1-g- Pt (1 wt %) 500 W high pressure Hg-lamp 10 mg dye-sensitized 1wt% Pt/g- photocatalyst in 10 ml of 50 mm AA aqueous solution and dyeloading amount on Pt/g- is 5.0 μmol g μmol g 1 4 Zn-tri-PcNc-TiO 2 Pt (1 wt %) 300W Xelamp, 420 nm 30 mg catalyst in a 20 ml EDTA solution (10 mm), 0.1 wt% Ptloading, 5 μmol g 1 dye-loading, original ph ( ) without adjustment μmol TON ~ Zn-tetra-Nc-TiO 2 Pt (1 wt %) 30 mg catalyst in a 20 ml EDTA solution (10 mm), 0.1 wt% Ptloading, 5 μmol g 1 dye-loading, original ph ( ) without S μmol TON ~3153 5

5 Zn-tri-PcNc-TiO 2 Pt (0.1 wt %) 300W Xelamp 420 nm adjustment 10 ml AA solution with different concentrations, 10 mg 0.1wt% Pt/TiO2, the ph (~1.50) of the AA solution is not adjusted to a specific value, 420 nm light irradiation μmol/h 6 Zn-Pc-HPT-500 Pt (1 wt %) 300W Xelamp, λ 450 nm 15 mg dye-sensitized 1wt% Pt/HPT-500 photocatalyst in 20 ml of 10 vol% TEOA aq. sol n and dye-loading amount on Pt/HPT-500 is 0.25 μmol 2260 μmol TON This work a Xe: xenon lamp, Hg: mercury lamp. b TEOA: triethanolamine, EDTA= Ethylenediaminetetraacetic acid References: 1. Zhang, X.; Yu, L.; Zhuang, C.; Peng, T.; Li, R.; Li, X. Highly Asymmetric Phthalocyanine as a Sensitizer of Graphitic Carbon Nitride for Extremely Efficient Photocatalytic H 2 Production under Near-Infrared Light. ACS Catal. 2014, 4, Zhang, X.; Peng, T.; Yu, L.; Li, R.; Li, Q.; Li, Z. Visible/Near-Infrared-Light-Induced H 2 Production over g- Co-sensitized by Organic Dye and Zinc Phthalocyanine Derivative. ACS Catal. 2015, 5, Yu, L.; Zhang, X.; Zhuang, C.; Lin, L.; Li, R.; Peng, T. Syntheses of Asymmetric Zinc Phthalocyanines as Sensitizer of Pt-loaded Graphitic Carbon Nitride for Efficient Visible/near-IR-light-driven H 2 Production, Phys. Chem. Chem. Phys., 2014, 16, S. Song, Y. Guo, T. Peng, J. Zhang and R. Li, Effects of the Symmetry and Carboxyl Anchoring Group of Zinc Phthalocyanine Derivatives on g- for Photosensitized H 2 Production. RSC Adv., 2016, 6, Zhang, X.; Yu, L.; Zhuang, C.; Peng, T.; Li, R.; Li, X. Highly Efficient Visible/near-IR-Light-Driven Photocatalytic H 2 Production over Asymmetric Phthalocyanine-Sensitized TiO 2, RSC Adv., 2013, 3, Zhang, X.; Peng, B.; Peng, T.; Yu, L.; Li, R.; Zhang, J. A New Route for Visible/near-infrared Light Driven H 2 Production over Titania: Co-Sensitization of Surface Charge Transfer Complex and Zinc Phthalocyanine. J. Power Sources, 2015, 298, S5