File Name : s1.tif Caption : xrd patterns of gqds. File Name : s2.tif Caption : (a) fluorescence emission intensities of the gqds at different excitation wavelengths. (b) uv-vis absorption spectrum of gqds. File Name : s3.tif Caption : the fesem image of porous nio films on fto glass substrate. File Name : s4.tif Caption : synthesis of complex [(tpy-ch=n)2ni]cl2. File Name : s5.tif Caption : the 1h nmr characterization for compound l1. File Name : s6.tif Caption : the 1h nmr characterization for compound l2. File Name : s7.tif Caption : high resolution mass spectrometry of [(tpy-ch=n)2ni]cl2. File Name : s8.tif Caption : the elemental mapping of nin-gqds-nio photocathode by edx spectroscopy. File Name : s9.tif Caption : xps scan spectrum of nin-gqds-nio photocathode at 0-1200 ev. File Name : s10.tif Caption : (a) photocurrent density of the gqds-nio electrodes with different dipping times. (b) photocurrent density of the nin-gqds-nio electrode with different nin co-catalyst loadings. File Name : s11.tif Caption : the hrtem image of the assembled nin-gqds-nio photocathode after photoelectric testing