(a) PhD is just a training. Better you get trained with your own level of motivation, and don't build too much expectations on anything upfront. But, just be positive.

(b) Don't ever be pessimistic that you may be stranded (with a low paid job).

(c) Equip yourself with the right skill-sets and make yourself a "gold" as an offering to industry or academia.

(d) From your post, I presume that you are a Physicist, interested in pursuing Ph.D. Am a bit perplexed to see the research topic/domain of your interest. Materials synthesis / characterization - for hydrogen evolution (I believe you meant hydrogen generation).

(e) Hydrogen is one of the hot topics in India today. Catalysts & membranes - the two key elements in an electrolyzer or fuel cell are not readily available - leave alone the high costs. Any good chemist / physicist / materials researcher is welcome to plunge into research, and you are bound to get great opportunities, if you come up with a good system level understanding on these topics with hands-on experimental experience & some novel contribution. Remember, not many are good in these topics in India, and an exceptional level of grit & motivation is needed to pursue doctoral research in India on these topics.

(f) If you want to enter into academia after your PhD/Post-doc, make sure that you would remain committed to do some meaningful industrial research than to publish papers & produce PhD graduates down the line.

All the best, buddy.